/** Purpose ------- DSYEVD computes all eigenvalues and, optionally, eigenvectors of a real symmetric matrix A. If eigenvectors are desired, it uses a divide and conquer algorithm. The divide and conquer algorithm makes very mild assumptions about floating point arithmetic. It will work on machines with a guard digit in add/subtract, or on those binary machines without guard digits which subtract like the Cray X-MP, Cray Y-MP, Cray C-90, or Cray-2. It could conceivably fail on hexadecimal or decimal machines without guard digits, but we know of none. Arguments --------- @param[in] nrgpu INTEGER Number of GPUs to use. @param[in] jobz magma_vec_t - = MagmaNoVec: Compute eigenvalues only; - = MagmaVec: Compute eigenvalues and eigenvectors. @param[in] uplo magma_uplo_t - = MagmaUpper: Upper triangle of A is stored; - = MagmaLower: Lower triangle of A is stored. @param[in] n INTEGER The order of the matrix A. N >= 0. @param[in,out] A DOUBLE_PRECISION array, dimension (LDA, N) On entry, the symmetric matrix A. If UPLO = MagmaUpper, the leading N-by-N upper triangular part of A contains the upper triangular part of the matrix A. If UPLO = MagmaLower, the leading N-by-N lower triangular part of A contains the lower triangular part of the matrix A. On exit, if JOBZ = MagmaVec, then if INFO = 0, A contains the orthonormal eigenvectors of the matrix A. If JOBZ = MagmaNoVec, then on exit the lower triangle (if UPLO=MagmaLower) or the upper triangle (if UPLO=MagmaUpper) of A, including the diagonal, is destroyed. @param[in] lda INTEGER The leading dimension of the array A. LDA >= max(1,N). @param[out] w DOUBLE PRECISION array, dimension (N) If INFO = 0, the eigenvalues in ascending order. @param[out] work (workspace) DOUBLE_PRECISION array, dimension (MAX(1,LWORK)) On exit, if INFO = 0, WORK[0] returns the optimal LWORK. @param[in] lwork INTEGER The length of the array WORK. If N <= 1, LWORK >= 1. If JOBZ = MagmaNoVec and N > 1, LWORK >= 2*N + N*NB. If JOBZ = MagmaVec and N > 1, LWORK >= max( 2*N + N*NB, 1 + 6*N + 2*N**2 ). NB can be obtained through magma_get_dsytrd_nb(N). \n If LWORK = -1, then a workspace query is assumed; the routine only calculates the optimal sizes of the WORK, RWORK and IWORK arrays, returns these values as the first entries of the WORK, RWORK and IWORK arrays, and no error message related to LWORK or LRWORK or LIWORK is issued by XERBLA. @param[out] iwork (workspace) INTEGER array, dimension (MAX(1,LIWORK)) On exit, if INFO = 0, IWORK[0] returns the optimal LIWORK. @param[in] liwork INTEGER The dimension of the array IWORK. If N <= 1, LIWORK >= 1. If JOBZ = MagmaNoVec and N > 1, LIWORK >= 1. If JOBZ = MagmaVec and N > 1, LIWORK >= 3 + 5*N. \n If LIWORK = -1, then a workspace query is assumed; the routine only calculates the optimal sizes of the WORK, RWORK and IWORK arrays, returns these values as the first entries of the WORK, RWORK and IWORK arrays, and no error message related to LWORK or LRWORK or LIWORK is issued by XERBLA. @param[out] info INTEGER - = 0: successful exit - < 0: if INFO = -i, the i-th argument had an illegal value - > 0: if INFO = i and JOBZ = MagmaNoVec, then the algorithm failed to converge; i off-diagonal elements of an intermediate tridiagonal form did not converge to zero; if INFO = i and JOBZ = MagmaVec, then the algorithm failed to compute an eigenvalue while working on the submatrix lying in rows and columns INFO/(N+1) through mod(INFO,N+1). Further Details --------------- Based on contributions by Jeff Rutter, Computer Science Division, University of California at Berkeley, USA Modified description of INFO. Sven, 16 Feb 05. @ingroup magma_dsyev_driver ********************************************************************/ extern "C" magma_int_t magma_dsyevd_m(magma_int_t nrgpu, magma_vec_t jobz, magma_uplo_t uplo, magma_int_t n, double *A, magma_int_t lda, double *w, double *work, magma_int_t lwork, magma_int_t *iwork, magma_int_t liwork, magma_int_t *info) { const char* uplo_ = lapack_uplo_const( uplo ); const char* jobz_ = lapack_vec_const( jobz ); magma_int_t ione = 1; magma_int_t izero = 0; double d_one = 1.; double d__1; double eps; magma_int_t inde; double anrm; double rmin, rmax; double sigma; magma_int_t iinfo, lwmin; magma_int_t lower; magma_int_t wantz; magma_int_t indwk2, llwrk2; magma_int_t iscale; double safmin; double bignum; magma_int_t indtau; magma_int_t indwrk, liwmin; magma_int_t llwork; double smlnum; magma_int_t lquery; wantz = (jobz == MagmaVec); lower = (uplo == MagmaLower); lquery = (lwork == -1 || liwork == -1); *info = 0; if (! (wantz || (jobz == MagmaNoVec))) { *info = -1; } else if (! (lower || (uplo == MagmaUpper))) { *info = -2; } else if (n < 0) { *info = -3; } else if (lda < max(1,n)) { *info = -5; } magma_int_t nb = magma_get_dsytrd_nb( n ); if ( n <= 1 ) { lwmin = 1; liwmin = 1; } else if ( wantz ) { lwmin = max( 2*n + n*nb, 1 + 6*n + 2*n*n ); liwmin = 3 + 5*n; } else { lwmin = 2*n + n*nb; liwmin = 1; } // multiply by 1+eps (in Double!) to ensure length gets rounded up, // if it cannot be exactly represented in floating point. real_Double_t one_eps = 1. + lapackf77_dlamch("Epsilon"); work[0] = lwmin * one_eps; iwork[0] = liwmin; if ((lwork < lwmin) && !lquery) { *info = -8; } else if ((liwork < liwmin) && ! lquery) { *info = -10; } if (*info != 0) { magma_xerbla( __func__, -(*info) ); return *info; } else if (lquery) { return *info; } /* Quick return if possible */ if (n == 0) { return *info; } if (n == 1) { w[0] = A[0]; if (wantz) { A[0] = 1.; } return *info; } /* Check if matrix is very small then just call LAPACK on CPU, no need for GPU */ if (n <= 128) { #ifdef ENABLE_DEBUG printf("--------------------------------------------------------------\n"); printf(" warning matrix too small N=%d NB=%d, calling lapack on CPU \n", (int) n, (int) nb); printf("--------------------------------------------------------------\n"); #endif lapackf77_dsyevd(jobz_, uplo_, &n, A, &lda, w, work, &lwork, iwork, &liwork, info); return *info; } /* Get machine constants. */ safmin = lapackf77_dlamch("Safe minimum"); eps = lapackf77_dlamch("Precision"); smlnum = safmin / eps; bignum = 1. / smlnum; rmin = magma_dsqrt(smlnum); rmax = magma_dsqrt(bignum); /* Scale matrix to allowable range, if necessary. */ anrm = lapackf77_dlansy("M", uplo_, &n, A, &lda, work); iscale = 0; if (anrm > 0. && anrm < rmin) { iscale = 1; sigma = rmin / anrm; } else if (anrm > rmax) { iscale = 1; sigma = rmax / anrm; } if (iscale == 1) { lapackf77_dlascl(uplo_, &izero, &izero, &d_one, &sigma, &n, &n, A, &lda, info); } /* Call DSYTRD to reduce symmetric matrix to tridiagonal form. */ // dsytrd work: e (n) + tau (n) + llwork (n*nb) ==> 2n + n*nb // dstedx work: e (n) + tau (n) + z (n*n) + llwrk2 (1 + 4*n + n^2) ==> 1 + 6n + 2n^2 inde = 0; indtau = inde + n; indwrk = indtau + n; indwk2 = indwrk + n*n; llwork = lwork - indwrk; llwrk2 = lwork - indwk2; magma_timer_t time=0; timer_start( time ); magma_dsytrd_mgpu(nrgpu, 1, uplo, n, A, lda, w, &work[inde], &work[indtau], &work[indwrk], llwork, &iinfo); timer_stop( time ); timer_printf( "time dsytrd = %6.2f\n", time ); /* For eigenvalues only, call DSTERF. For eigenvectors, first call DSTEDC to generate the eigenvector matrix, WORK(INDWRK), of the tridiagonal matrix, then call DORMTR to multiply it to the Householder transformations represented as Householder vectors in A. */ if (! wantz) { lapackf77_dsterf(&n, w, &work[inde], info); } else { timer_start( time ); #ifdef USE_SINGLE_GPU if (MAGMA_SUCCESS != magma_dmalloc( &dwork, 3*n*(n/2 + 1) )) { *info = MAGMA_ERR_DEVICE_ALLOC; return *info; } magma_dstedx(MagmaRangeAll, n, 0., 0., 0, 0, w, &work[inde], &work[indwrk], n, &work[indwk2], llwrk2, iwork, liwork, dwork, info); magma_free( dwork ); #else magma_dstedx_m(nrgpu, MagmaRangeAll, n, 0., 0., 0, 0, w, &work[inde], &work[indwrk], n, &work[indwk2], llwrk2, iwork, liwork, info); #endif timer_stop( time ); timer_printf( "time dstedc = %6.2f\n", time ); timer_start( time ); magma_dormtr_m(nrgpu, MagmaLeft, uplo, MagmaNoTrans, n, n, A, lda, &work[indtau], &work[indwrk], n, &work[indwk2], llwrk2, &iinfo); lapackf77_dlacpy("A", &n, &n, &work[indwrk], &n, A, &lda); timer_stop( time ); timer_printf( "time dormtr + copy = %6.2f\n", time ); } /* If matrix was scaled, then rescale eigenvalues appropriately. */ if (iscale == 1) { d__1 = 1. / sigma; blasf77_dscal(&n, &d__1, w, &ione); } work[0] = lwmin * one_eps; // round up iwork[0] = liwmin; return *info; } /* magma_dsyevd_m */
extern "C" magma_int_t magma_zheevx_gpu(char jobz, char range, char uplo, magma_int_t n, magmaDoubleComplex *da, magma_int_t ldda, double vl, double vu, magma_int_t il, magma_int_t iu, double abstol, magma_int_t *m, double *w, magmaDoubleComplex *dz, magma_int_t lddz, magmaDoubleComplex *wa, magma_int_t ldwa, magmaDoubleComplex *wz, magma_int_t ldwz, magmaDoubleComplex *work, magma_int_t lwork, double *rwork, magma_int_t *iwork, magma_int_t *ifail, magma_int_t *info) { /* -- MAGMA (version 1.4.1) -- Univ. of Tennessee, Knoxville Univ. of California, Berkeley Univ. of Colorado, Denver December 2013 Purpose ======= ZHEEVX computes selected eigenvalues and, optionally, eigenvectors of a complex Hermitian matrix A. Eigenvalues and eigenvectors can be selected by specifying either a range of values or a range of indices for the desired eigenvalues. Arguments ========= JOBZ (input) CHARACTER*1 = 'N': Compute eigenvalues only; = 'V': Compute eigenvalues and eigenvectors. RANGE (input) CHARACTER*1 = 'A': all eigenvalues will be found. = 'V': all eigenvalues in the half-open interval (VL,VU] will be found. = 'I': the IL-th through IU-th eigenvalues will be found. UPLO (input) CHARACTER*1 = 'U': Upper triangle of A is stored; = 'L': Lower triangle of A is stored. N (input) INTEGER The order of the matrix A. N >= 0. DA (device input/output) COMPLEX_16 array, dimension (LDDA, N) On entry, the Hermitian matrix A. If UPLO = 'U', the leading N-by-N upper triangular part of A contains the upper triangular part of the matrix A. If UPLO = 'L', the leading N-by-N lower triangular part of A contains the lower triangular part of the matrix A. On exit, the lower triangle (if UPLO='L') or the upper triangle (if UPLO='U') of A, including the diagonal, is destroyed. LDDA (input) INTEGER The leading dimension of the array DA. LDDA >= max(1,N). VL (input) DOUBLE PRECISION VU (input) DOUBLE PRECISION If RANGE='V', the lower and upper bounds of the interval to be searched for eigenvalues. VL < VU. Not referenced if RANGE = 'A' or 'I'. IL (input) INTEGER IU (input) INTEGER If RANGE='I', the indices (in ascending order) of the smallest and largest eigenvalues to be returned. 1 <= IL <= IU <= N, if N > 0; IL = 1 and IU = 0 if N = 0. Not referenced if RANGE = 'A' or 'V'. ABSTOL (input) DOUBLE PRECISION The absolute error tolerance for the eigenvalues. An approximate eigenvalue is accepted as converged when it is determined to lie in an interval [a,b] of width less than or equal to ABSTOL + EPS * max( |a|,|b| ) , where EPS is the machine precision. If ABSTOL is less than or equal to zero, then EPS*|T| will be used in its place, where |T| is the 1-norm of the tridiagonal matrix obtained by reducing A to tridiagonal form. Eigenvalues will be computed most accurately when ABSTOL is set to twice the underflow threshold 2*DLAMCH('S'), not zero. If this routine returns with INFO>0, indicating that some eigenvectors did not converge, try setting ABSTOL to 2*DLAMCH('S'). See "Computing Small Singular Values of Bidiagonal Matrices with Guaranteed High Relative Accuracy," by Demmel and Kahan, LAPACK Working Note #3. M (output) INTEGER The total number of eigenvalues found. 0 <= M <= N. If RANGE = 'A', M = N, and if RANGE = 'I', M = IU-IL+1. W (output) DOUBLE PRECISION array, dimension (N) On normal exit, the first M elements contain the selected eigenvalues in ascending order. DZ (device output) COMPLEX_16 array, dimension (LDDZ, max(1,M)) If JOBZ = 'V', then if INFO = 0, the first M columns of Z contain the orthonormal eigenvectors of the matrix A corresponding to the selected eigenvalues, with the i-th column of Z holding the eigenvector associated with W(i). If an eigenvector fails to converge, then that column of Z contains the latest approximation to the eigenvector, and the index of the eigenvector is returned in IFAIL. If JOBZ = 'N', then Z is not referenced. Note: the user must ensure that at least max(1,M) columns are supplied in the array Z; if RANGE = 'V', the exact value of M is not known in advance and an upper bound must be used. ********* (workspace) If FAST_HEMV is defined DZ should be (LDDZ, max(1,N)) in both cases. LDDZ (input) INTEGER The leading dimension of the array DZ. LDDZ >= 1, and if JOBZ = 'V', LDDZ >= max(1,N). WA (workspace) COMPLEX_16 array, dimension (LDWA, N) LDWA (input) INTEGER The leading dimension of the array WA. LDWA >= max(1,N). WZ (workspace) COMPLEX_16 array, dimension (LDWZ, max(1,M)) LDWZ (input) INTEGER The leading dimension of the array DZ. LDWZ >= 1, and if JOBZ = 'V', LDWZ >= max(1,N). WORK (workspace/output) COMPLEX_16 array, dimension (LWORK) On exit, if INFO = 0, WORK(1) returns the optimal LWORK. LWORK (input) INTEGER The length of the array WORK. LWORK >= (NB+1)*N, where NB is the max of the blocksize for ZHETRD. If LWORK = -1, then a workspace query is assumed; the routine only calculates the optimal size of the WORK array, returns this value as the first entry of the WORK array, and no error message related to LWORK is issued by XERBLA. RWORK (workspace) DOUBLE PRECISION array, dimension (7*N) IWORK (workspace) INTEGER array, dimension (5*N) IFAIL (output) INTEGER array, dimension (N) If JOBZ = 'V', then if INFO = 0, the first M elements of IFAIL are zero. If INFO > 0, then IFAIL contains the indices of the eigenvectors that failed to converge. If JOBZ = 'N', then IFAIL is not referenced. INFO (output) INTEGER = 0: successful exit < 0: if INFO = -i, the i-th argument had an illegal value > 0: if INFO = i, then i eigenvectors failed to converge. Their indices are stored in array IFAIL. ===================================================================== */ char uplo_[2] = {uplo, 0}; char jobz_[2] = {jobz, 0}; char range_[2] = {range, 0}; magma_int_t ione = 1; char order[1]; magma_int_t indd, inde; magma_int_t imax; magma_int_t lopt, itmp1, indee; magma_int_t lower, wantz; magma_int_t i, j, jj, i__1; magma_int_t alleig, valeig, indeig; magma_int_t iscale, indibl; magma_int_t indiwk, indisp, indtau; magma_int_t indrwk, indwrk; magma_int_t llwork, nsplit; magma_int_t lquery; magma_int_t iinfo; double safmin; double bignum; double smlnum; double eps, tmp1; double anrm; double sigma, d__1; double rmin, rmax; double *dwork; /* Function Body */ lower = lapackf77_lsame(uplo_, MagmaLowerStr); wantz = lapackf77_lsame(jobz_, MagmaVecStr); alleig = lapackf77_lsame(range_, "A"); valeig = lapackf77_lsame(range_, "V"); indeig = lapackf77_lsame(range_, "I"); lquery = lwork == -1; *info = 0; if (! (wantz || lapackf77_lsame(jobz_, MagmaNoVecStr))) { *info = -1; } else if (! (alleig || valeig || indeig)) { *info = -2; } else if (! (lower || lapackf77_lsame(uplo_, MagmaUpperStr))) { *info = -3; } else if (n < 0) { *info = -4; } else if (ldda < max(1,n)) { *info = -6; } else if (lddz < 1 || (wantz && lddz < n)) { *info = -15; } else if (ldwa < max(1,n)) { *info = -17; } else if (ldwz < 1 || (wantz && ldwz < n)) { *info = -19; } else { if (valeig) { if (n > 0 && vu <= vl) { *info = -8; } } else if (indeig) { if (il < 1 || il > max(1,n)) { *info = -9; } else if (iu < min(n,il) || iu > n) { *info = -10; } } } magma_int_t nb = magma_get_zhetrd_nb(n); lopt = n * (nb + 1); work[0] = MAGMA_Z_MAKE( lopt, 0 ); if (lwork < lopt && ! lquery) { *info = -21; } if (*info != 0) { magma_xerbla( __func__, -(*info)); return *info; } else if (lquery) { return *info; } *m = 0; /* Check if matrix is very small then just call LAPACK on CPU, no need for GPU */ if (n <= 128) { #ifdef ENABLE_DEBUG printf("--------------------------------------------------------------\n"); printf(" warning matrix too small N=%d NB=%d, calling lapack on CPU \n", (int) n, (int) nb); printf("--------------------------------------------------------------\n"); #endif magmaDoubleComplex *a = (magmaDoubleComplex *) malloc( n * n * sizeof(magmaDoubleComplex) ); magma_zgetmatrix(n, n, da, ldda, a, n); lapackf77_zheevx(jobz_, range_, uplo_, &n, a, &n, &vl, &vu, &il, &iu, &abstol, m, w, wz, &ldwz, work, &lwork, rwork, iwork, ifail, info); magma_zsetmatrix( n, n, a, n, da, ldda); magma_zsetmatrix( n, *m, wz, ldwz, dz, lddz); free(a); return *info; } if (MAGMA_SUCCESS != magma_dmalloc( &dwork, n )) { fprintf (stderr, "!!!! device memory allocation error (magma_zheevx_gpu)\n"); *info = MAGMA_ERR_DEVICE_ALLOC; return *info; } --w; --work; --rwork; --iwork; --ifail; /* Get machine constants. */ safmin = lapackf77_dlamch("Safe minimum"); eps = lapackf77_dlamch("Precision"); smlnum = safmin / eps; bignum = 1. / smlnum; rmin = magma_dsqrt(smlnum); rmax = magma_dsqrt(bignum); /* Scale matrix to allowable range, if necessary. */ anrm = magmablas_zlanhe('M', uplo, n, da, ldda, dwork); iscale = 0; sigma = 1; if (anrm > 0. && anrm < rmin) { iscale = 1; sigma = rmin / anrm; } else if (anrm > rmax) { iscale = 1; sigma = rmax / anrm; } if (iscale == 1) { d__1 = 1.; magmablas_zlascl(uplo, 0, 0, 1., sigma, n, n, da, ldda, info); if (abstol > 0.) { abstol *= sigma; } if (valeig) { vl *= sigma; vu *= sigma; } } /* Call ZHETRD to reduce Hermitian matrix to tridiagonal form. */ indd = 1; inde = indd + n; indrwk = inde + n; indtau = 1; indwrk = indtau + n; llwork = lwork - indwrk + 1; #ifdef FAST_HEMV magma_zhetrd2_gpu(uplo, n, da, ldda, &rwork[indd], &rwork[inde], &work[indtau], wa, ldwa, &work[indwrk], llwork, dz, lddz*n, &iinfo); #else magma_zhetrd_gpu (uplo, n, da, ldda, &rwork[indd], &rwork[inde], &work[indtau], wa, ldwa, &work[indwrk], llwork, &iinfo); #endif lopt = n + (magma_int_t)MAGMA_Z_REAL(work[indwrk]); /* If all eigenvalues are desired and ABSTOL is less than or equal to zero, then call DSTERF or ZUNGTR and ZSTEQR. If this fails for some eigenvalue, then try DSTEBZ. */ if ((alleig || (indeig && il == 1 && iu == n)) && abstol <= 0.) { blasf77_dcopy(&n, &rwork[indd], &ione, &w[1], &ione); indee = indrwk + 2*n; if (! wantz) { i__1 = n - 1; blasf77_dcopy(&i__1, &rwork[inde], &ione, &rwork[indee], &ione); lapackf77_dsterf(&n, &w[1], &rwork[indee], info); } else { lapackf77_zlacpy("A", &n, &n, wa, &ldwa, wz, &ldwz); lapackf77_zungtr(uplo_, &n, wz, &ldwz, &work[indtau], &work[indwrk], &llwork, &iinfo); i__1 = n - 1; blasf77_dcopy(&i__1, &rwork[inde], &ione, &rwork[indee], &ione); lapackf77_zsteqr(jobz_, &n, &w[1], &rwork[indee], wz, &ldwz, &rwork[indrwk], info); if (*info == 0) { for (i = 1; i <= n; ++i) { ifail[i] = 0; } magma_zsetmatrix( n, n, wz, ldwz, dz, lddz ); } } if (*info == 0) { *m = n; } } /* Otherwise, call DSTEBZ and, if eigenvectors are desired, ZSTEIN. */ if (*m == 0) { *info = 0; if (wantz) { *(unsigned char *)order = 'B'; } else { *(unsigned char *)order = 'E'; } indibl = 1; indisp = indibl + n; indiwk = indisp + n; lapackf77_dstebz(range_, order, &n, &vl, &vu, &il, &iu, &abstol, &rwork[indd], &rwork[inde], m, &nsplit, &w[1], &iwork[indibl], &iwork[indisp], &rwork[indrwk], &iwork[indiwk], info); if (wantz) { lapackf77_zstein(&n, &rwork[indd], &rwork[inde], m, &w[1], &iwork[indibl], &iwork[indisp], wz, &ldwz, &rwork[indrwk], &iwork[indiwk], &ifail[1], info); magma_zsetmatrix( n, *m, wz, ldwz, dz, lddz ); /* Apply unitary matrix used in reduction to tridiagonal form to eigenvectors returned by ZSTEIN. */ magma_zunmtr_gpu(MagmaLeft, uplo, MagmaNoTrans, n, *m, da, ldda, &work[indtau], dz, lddz, wa, ldwa, &iinfo); } } /* If matrix was scaled, then rescale eigenvalues appropriately. */ if (iscale == 1) { if (*info == 0) { imax = *m; } else { imax = *info - 1; } d__1 = 1. / sigma; blasf77_dscal(&imax, &d__1, &w[1], &ione); } /* If eigenvalues are not in order, then sort them, along with eigenvectors. */ if (wantz) { for (j = 1; j <= *m-1; ++j) { i = 0; tmp1 = w[j]; for (jj = j + 1; jj <= *m; ++jj) { if (w[jj] < tmp1) { i = jj; tmp1 = w[jj]; } } if (i != 0) { itmp1 = iwork[indibl + i - 1]; w[i] = w[j]; iwork[indibl + i - 1] = iwork[indibl + j - 1]; w[j] = tmp1; iwork[indibl + j - 1] = itmp1; magma_zswap(n, dz + (i-1)*lddz, ione, dz + (j-1)*lddz, ione); if (*info != 0) { itmp1 = ifail[i]; ifail[i] = ifail[j]; ifail[j] = itmp1; } } } } /* Set WORK(1) to optimal complex workspace size. */ work[1] = MAGMA_Z_MAKE( lopt, 0 ); return *info; } /* magma_zheevx_gpu */
extern "C" magma_int_t magma_zheevdx_2stage(char jobz, char range, char uplo, magma_int_t n, magmaDoubleComplex *a, magma_int_t lda, double vl, double vu, magma_int_t il, magma_int_t iu, magma_int_t *m, double *w, magmaDoubleComplex *work, magma_int_t lwork, double *rwork, magma_int_t lrwork, magma_int_t *iwork, magma_int_t liwork, magma_int_t *info) { /* -- MAGMA (version 1.4.0) -- Univ. of Tennessee, Knoxville Univ. of California, Berkeley Univ. of Colorado, Denver August 2013 Purpose ======= ZHEEVD_2STAGE computes all eigenvalues and, optionally, eigenvectors of a complex Hermitian matrix A. It uses a two-stage algorithm for the tridiagonalization. If eigenvectors are desired, it uses a divide and conquer algorithm. The divide and conquer algorithm makes very mild assumptions about floating point arithmetic. It will work on machines with a guard digit in add/subtract, or on those binary machines without guard digits which subtract like the Cray X-MP, Cray Y-MP, Cray C-90, or Cray-2. It could conceivably fail on hexadecimal or decimal machines without guard digits, but we know of none. Arguments ========= JOBZ (input) CHARACTER*1 = 'N': Compute eigenvalues only; = 'V': Compute eigenvalues and eigenvectors. RANGE (input) CHARACTER*1 = 'A': all eigenvalues will be found. = 'V': all eigenvalues in the half-open interval (VL,VU] will be found. = 'I': the IL-th through IU-th eigenvalues will be found. UPLO (input) CHARACTER*1 = 'U': Upper triangle of A is stored; = 'L': Lower triangle of A is stored. N (input) INTEGER The order of the matrix A. N >= 0. A (input/output) COMPLEX_16 array, dimension (LDA, N) On entry, the Hermitian matrix A. If UPLO = 'U', the leading N-by-N upper triangular part of A contains the upper triangular part of the matrix A. If UPLO = 'L', the leading N-by-N lower triangular part of A contains the lower triangular part of the matrix A. On exit, if JOBZ = 'V', then if INFO = 0, the first m columns of A contains the required orthonormal eigenvectors of the matrix A. If JOBZ = 'N', then on exit the lower triangle (if UPLO='L') or the upper triangle (if UPLO='U') of A, including the diagonal, is destroyed. LDA (input) INTEGER The leading dimension of the array A. LDA >= max(1,N). VL (input) DOUBLE PRECISION VU (input) DOUBLE PRECISION If RANGE='V', the lower and upper bounds of the interval to be searched for eigenvalues. VL < VU. Not referenced if RANGE = 'A' or 'I'. IL (input) INTEGER IU (input) INTEGER If RANGE='I', the indices (in ascending order) of the smallest and largest eigenvalues to be returned. 1 <= IL <= IU <= N, if N > 0; IL = 1 and IU = 0 if N = 0. Not referenced if RANGE = 'A' or 'V'. M (output) INTEGER The total number of eigenvalues found. 0 <= M <= N. If RANGE = 'A', M = N, and if RANGE = 'I', M = IU-IL+1. W (output) DOUBLE PRECISION array, dimension (N) If INFO = 0, the required m eigenvalues in ascending order. WORK (workspace/output) COMPLEX_16 array, dimension (MAX(1,LWORK)) On exit, if INFO = 0, WORK(1) returns the optimal LWORK. LWORK (input) INTEGER The length of the array WORK. If N <= 1, LWORK >= 1. If JOBZ = 'N' and N > 1, LWORK >= LQ2 + N * (NB + 1). If JOBZ = 'V' and N > 1, LWORK >= LQ2 + 2*N + N**2. where LQ2 is the size needed to store the Q2 matrix and is returned by MAGMA_BULGE_GET_LQ2. If LWORK = -1, then a workspace query is assumed; the routine only calculates the optimal sizes of the WORK, RWORK and IWORK arrays, returns these values as the first entries of the WORK, RWORK and IWORK arrays, and no error message related to LWORK or LRWORK or LIWORK is issued by XERBLA. RWORK (workspace/output) DOUBLE PRECISION array, dimension (LRWORK) On exit, if INFO = 0, RWORK(1) returns the optimal LRWORK. LRWORK (input) INTEGER The dimension of the array RWORK. If N <= 1, LRWORK >= 1. If JOBZ = 'N' and N > 1, LRWORK >= N. If JOBZ = 'V' and N > 1, LRWORK >= 1 + 5*N + 2*N**2. If LRWORK = -1, then a workspace query is assumed; the routine only calculates the optimal sizes of the WORK, RWORK and IWORK arrays, returns these values as the first entries of the WORK, RWORK and IWORK arrays, and no error message related to LWORK or LRWORK or LIWORK is issued by XERBLA. IWORK (workspace/output) INTEGER array, dimension (MAX(1,LIWORK)) On exit, if INFO = 0, IWORK(1) returns the optimal LIWORK. LIWORK (input) INTEGER The dimension of the array IWORK. If N <= 1, LIWORK >= 1. If JOBZ = 'N' and N > 1, LIWORK >= 1. If JOBZ = 'V' and N > 1, LIWORK >= 3 + 5*N. If LIWORK = -1, then a workspace query is assumed; the routine only calculates the optimal sizes of the WORK, RWORK and IWORK arrays, returns these values as the first entries of the WORK, RWORK and IWORK arrays, and no error message related to LWORK or LRWORK or LIWORK is issued by XERBLA. INFO (output) INTEGER = 0: successful exit < 0: if INFO = -i, the i-th argument had an illegal value > 0: if INFO = i and JOBZ = 'N', then the algorithm failed to converge; i off-diagonal elements of an intermediate tridiagonal form did not converge to zero; if INFO = i and JOBZ = 'V', then the algorithm failed to compute an eigenvalue while working on the submatrix lying in rows and columns INFO/(N+1) through mod(INFO,N+1). Further Details =============== Based on contributions by Jeff Rutter, Computer Science Division, University of California at Berkeley, USA Modified description of INFO. Sven, 16 Feb 05. ===================================================================== */ char uplo_[2] = {uplo, 0}; char jobz_[2] = {jobz, 0}; char range_[2] = {range, 0}; magmaDoubleComplex c_one = MAGMA_Z_ONE; magma_int_t ione = 1; magma_int_t izero = 0; double d_one = 1.; double d__1; double eps; double anrm; magma_int_t imax; double rmin, rmax; double sigma; //magma_int_t iinfo; magma_int_t lwmin, lrwmin, liwmin; magma_int_t lower; magma_int_t wantz; magma_int_t iscale; double safmin; double bignum; double smlnum; magma_int_t lquery; magma_int_t alleig, valeig, indeig; double* dwork; /* determine the number of threads */ magma_int_t threads = magma_get_numthreads(); magma_setlapack_numthreads(threads); wantz = lapackf77_lsame(jobz_, MagmaVecStr); lower = lapackf77_lsame(uplo_, MagmaLowerStr); alleig = lapackf77_lsame( range_, "A" ); valeig = lapackf77_lsame( range_, "V" ); indeig = lapackf77_lsame( range_, "I" ); lquery = lwork == -1 || lrwork == -1 || liwork == -1; *info = 0; if (! (wantz || lapackf77_lsame(jobz_, MagmaNoVecStr))) { *info = -1; } else if (! (alleig || valeig || indeig)) { *info = -2; } else if (! (lower || lapackf77_lsame(uplo_, MagmaUpperStr))) { *info = -3; } else if (n < 0) { *info = -4; } else if (lda < max(1,n)) { *info = -6; } else { if (valeig) { if (n > 0 && vu <= vl) { *info = -8; } } else if (indeig) { if (il < 1 || il > max(1,n)) { *info = -9; } else if (iu < min(n,il) || iu > n) { *info = -10; } } } magma_int_t nb = magma_get_zbulge_nb(n,threads); magma_int_t Vblksiz = magma_zbulge_get_Vblksiz(n, nb, threads); magma_int_t ldt = Vblksiz; magma_int_t ldv = nb + Vblksiz; magma_int_t blkcnt = magma_bulge_get_blkcnt(n, nb, Vblksiz); magma_int_t lq2 = magma_zbulge_get_lq2(n, threads); if (wantz) { lwmin = lq2 + 2 * n + n * n; lrwmin = 1 + 5 * n + 2 * n * n; liwmin = 5 * n + 3; } else { lwmin = lq2 + n * (nb + 1); lrwmin = n; liwmin = 1; } work[0] = MAGMA_Z_MAKE( lwmin * (1. + lapackf77_dlamch("Epsilon")), 0.); // round up rwork[0] = lrwmin * (1. + lapackf77_dlamch("Epsilon")); iwork[0] = liwmin; if ((lwork < lwmin) && !lquery) { *info = -14; } else if ((lrwork < lrwmin) && ! lquery) { *info = -16; } else if ((liwork < liwmin) && ! lquery) { *info = -18; } if (*info != 0) { magma_xerbla( __func__, -(*info) ); return *info; } else if (lquery) { return *info; } /* Quick return if possible */ if (n == 0) { return *info; } if (n == 1) { w[0] = MAGMA_Z_REAL(a[0]); if (wantz) { a[0] = MAGMA_Z_ONE; } return *info; } #ifdef ENABLE_TIMER printf("using %d threads\n", threads); #endif /* Check if matrix is very small then just call LAPACK on CPU, no need for GPU */ magma_int_t ntiles = n/nb; if( ( ntiles < 2 ) || ( n <= 128 ) ){ #ifdef ENABLE_DEBUG printf("--------------------------------------------------------------\n"); printf(" warning matrix too small N=%d NB=%d, calling lapack on CPU \n", (int) n, (int) nb); printf("--------------------------------------------------------------\n"); #endif lapackf77_zheevd(jobz_, &uplo, &n, a, &lda, w, work, &lwork, #if defined(PRECISION_z) || defined(PRECISION_c) rwork, &lrwork, #endif iwork, &liwork, info); *m = n; return *info; } /* Get machine constants. */ safmin = lapackf77_dlamch("Safe minimum"); eps = lapackf77_dlamch("Precision"); smlnum = safmin / eps; bignum = 1. / smlnum; rmin = magma_dsqrt(smlnum); rmax = magma_dsqrt(bignum); /* Scale matrix to allowable range, if necessary. */ anrm = lapackf77_zlanhe("M", uplo_, &n, a, &lda, rwork); iscale = 0; if (anrm > 0. && anrm < rmin) { iscale = 1; sigma = rmin / anrm; } else if (anrm > rmax) { iscale = 1; sigma = rmax / anrm; } if (iscale == 1) { lapackf77_zlascl(uplo_, &izero, &izero, &d_one, &sigma, &n, &n, a, &lda, info); } magma_int_t indT2 = 0; magma_int_t indTAU2 = indT2 + blkcnt*ldt*Vblksiz; magma_int_t indV2 = indTAU2+ blkcnt*Vblksiz; magma_int_t indtau1 = indV2 + blkcnt*ldv*Vblksiz; magma_int_t indwrk = indtau1+ n; //magma_int_t indwk2 = indwrk + n * n; magma_int_t llwork = lwork - indwrk; //magma_int_t llwrk2 = lwork - indwk2; magma_int_t inde = 0; magma_int_t indrwk = inde + n; magma_int_t llrwk = lrwork - indrwk; #ifdef ENABLE_TIMER magma_timestr_t start, st1, st2, end; start = get_current_time(); #endif magmaDoubleComplex *dT1; if (MAGMA_SUCCESS != magma_zmalloc( &dT1, n*nb)) { *info = MAGMA_ERR_DEVICE_ALLOC; return *info; } magma_zhetrd_he2hb(uplo, n, nb, a, lda, &work[indtau1], &work[indwrk], llwork, dT1, threads, info); #ifdef ENABLE_TIMER st1 = get_current_time(); printf(" time zhetrd_he2hb = %6.2f\n" , GetTimerValue(start,st1)/1000.); #endif /* copy the input matrix into WORK(INDWRK) with band storage */ /* PAY ATTENTION THAT work[indwrk] should be able to be of size lda2*n which it should be checked in any future modification of lwork.*/ magma_int_t lda2 = 2*nb; //nb+1+(nb-1); magmaDoubleComplex* A2 = &work[indwrk]; memset(A2 , 0, n*lda2*sizeof(magmaDoubleComplex)); for (magma_int_t j = 0; j < n-nb; j++) { cblas_zcopy(nb+1, &a[j*(lda+1)], 1, &A2[j*lda2], 1); memset(&a[j*(lda+1)], 0, (nb+1)*sizeof(magmaDoubleComplex)); a[nb + j*(lda+1)] = c_one; } for (magma_int_t j = 0; j < nb; j++) { cblas_zcopy(nb-j, &a[(j+n-nb)*(lda+1)], 1, &A2[(j+n-nb)*lda2], 1); memset(&a[(j+n-nb)*(lda+1)], 0, (nb-j)*sizeof(magmaDoubleComplex)); } #ifdef ENABLE_TIMER st2 = get_current_time(); printf(" time zhetrd_convert = %6.2f\n" , GetTimerValue(st1,st2)/1000.); #endif magma_zhetrd_hb2st(threads, uplo, n, nb, Vblksiz, A2, lda2, w, &rwork[inde], &work[indV2], ldv, &work[indTAU2], wantz, &work[indT2], ldt); #ifdef ENABLE_TIMER end = get_current_time(); printf(" time zhetrd_hb2st = %6.2f\n" , GetTimerValue(st2,end)/1000.); printf(" time zhetrd = %6.2f\n", GetTimerValue(start,end)/1000.); #endif /* For eigenvalues only, call DSTERF. For eigenvectors, first call ZSTEDC to generate the eigenvector matrix, WORK(INDWRK), of the tridiagonal matrix, then call ZUNMTR to multiply it to the Householder transformations represented as Householder vectors in A. */ if (! wantz) { #ifdef ENABLE_TIMER start = get_current_time(); #endif lapackf77_dsterf(&n, w, &rwork[inde], info); magma_dmove_eig(range, n, w, &il, &iu, vl, vu, m); #ifdef ENABLE_TIMER end = get_current_time(); printf(" time dstedc = %6.2f\n", GetTimerValue(start,end)/1000.); #endif } else { #ifdef ENABLE_TIMER start = get_current_time(); #endif if (MAGMA_SUCCESS != magma_dmalloc( &dwork, 3*n*(n/2 + 1) )) { *info = MAGMA_ERR_DEVICE_ALLOC; return *info; } magma_zstedx(range, n, vl, vu, il, iu, w, &rwork[inde], &work[indwrk], n, &rwork[indrwk], llrwk, iwork, liwork, dwork, info); magma_free( dwork ); #ifdef ENABLE_TIMER end = get_current_time(); printf(" time zstedx = %6.2f\n", GetTimerValue(start,end)/1000.); start = get_current_time(); #endif magmaDoubleComplex *dZ; magma_int_t lddz = n; magmaDoubleComplex *da; magma_int_t ldda = n; magma_dmove_eig(range, n, w, &il, &iu, vl, vu, m); if (MAGMA_SUCCESS != magma_zmalloc( &dZ, *m*lddz)) { *info = MAGMA_ERR_DEVICE_ALLOC; return *info; } if (MAGMA_SUCCESS != magma_zmalloc( &da, n*ldda )) { *info = MAGMA_ERR_DEVICE_ALLOC; return *info; } magma_zbulge_back(threads, uplo, n, nb, *m, Vblksiz, &work[indwrk + n * (il-1)], n, dZ, lddz, &work[indV2], ldv, &work[indTAU2], &work[indT2], ldt, info); #ifdef ENABLE_TIMER st1 = get_current_time(); printf(" time zbulge_back = %6.2f\n" , GetTimerValue(start,st1)/1000.); #endif magma_zsetmatrix( n, n, a, lda, da, ldda ); magma_zunmqr_gpu_2stages(MagmaLeft, MagmaNoTrans, n-nb, *m, n-nb, da+nb, ldda, dZ+nb, n, dT1, nb, info); magma_zgetmatrix( n, *m, dZ, lddz, a, lda ); magma_free(dT1); magma_free(dZ); magma_free(da); #ifdef ENABLE_TIMER end = get_current_time(); printf(" time zunmqr + copy = %6.2f\n", GetTimerValue(st1,end)/1000.); printf(" time eigenvectors backtransf. = %6.2f\n" , GetTimerValue(start,end)/1000.); #endif } /* If matrix was scaled, then rescale eigenvalues appropriately. */ if (iscale == 1) { if (*info == 0) { imax = n; } else { imax = *info - 1; } d__1 = 1. / sigma; blasf77_dscal(&imax, &d__1, w, &ione); } work[0] = MAGMA_Z_MAKE( lwmin * (1. + lapackf77_dlamch("Epsilon")), 0.); // round up rwork[0] = lrwmin * (1. + lapackf77_dlamch("Epsilon")); iwork[0] = liwmin; return *info; } /* magma_zheevdx_2stage */
extern "C" magma_int_t magma_dsyevd( magma_vec_t jobz, magma_uplo_t uplo, magma_int_t n, double *a, magma_int_t lda, double *w, double *work, magma_int_t lwork, magma_int_t *iwork, magma_int_t liwork, magma_queue_t queue, magma_int_t *info) { /* -- MAGMA (version 1.3.0) -- Univ. of Tennessee, Knoxville Univ. of California, Berkeley Univ. of Colorado, Denver @date November 2014 Purpose ======= DSYEVD computes all eigenvalues and, optionally, eigenvectors of a real symmetric matrix A. If eigenvectors are desired, it uses a divide and conquer algorithm. The divide and conquer algorithm makes very mild assumptions about floating point arithmetic. It will work on machines with a guard digit in add/subtract, or on those binary machines without guard digits which subtract like the Cray X-MP, Cray Y-MP, Cray C-90, or Cray-2. It could conceivably fail on hexadecimal or decimal machines without guard digits, but we know of none. Arguments ========= JOBZ (input) CHARACTER*1 = 'N': Compute eigenvalues only; = 'V': Compute eigenvalues and eigenvectors. UPLO (input) CHARACTER*1 = 'U': Upper triangle of A is stored; = 'L': Lower triangle of A is stored. N (input) INTEGER The order of the matrix A. N >= 0. A (input/output) DOUBLE_PRECISION array, dimension (LDA, N) On entry, the symmetric matrix A. If UPLO = 'U', the leading N-by-N upper triangular part of A contains the upper triangular part of the matrix A. If UPLO = 'L', the leading N-by-N lower triangular part of A contains the lower triangular part of the matrix A. On exit, if JOBZ = 'V', then if INFO = 0, A contains the orthonormal eigenvectors of the matrix A. If JOBZ = 'N', then on exit the lower triangle (if UPLO='L') or the upper triangle (if UPLO='U') of A, including the diagonal, is destroyed. LDA (input) INTEGER The leading dimension of the array A. LDA >= max(1,N). W (output) DOUBLE PRECISION array, dimension (N) If INFO = 0, the eigenvalues in ascending order. WORK (workspace/output) DOUBLE_PRECISION array, dimension (MAX(1,LWORK)) On exit, if INFO = 0, WORK[0] returns the optimal LWORK. LWORK (input) INTEGER The length of the array WORK. If N <= 1, LWORK >= 1. If JOBZ = 'N' and N > 1, LWORK >= 2*N + N*NB. If JOBZ = 'V' and N > 1, LWORK >= max( 2*N + N*NB, 1 + 6*N + 2*N**2 ). NB can be obtained through magma_get_dsytrd_nb(N). If LWORK = -1, then a workspace query is assumed; the routine only calculates the optimal sizes of the WORK and IWORK arrays, returns these values as the first entries of the WORK and IWORK arrays, and no error message related to LWORK or LIWORK is issued by XERBLA. IWORK (workspace/output) INTEGER array, dimension (MAX(1,LIWORK)) On exit, if INFO = 0, IWORK[0] returns the optimal LIWORK. LIWORK (input) INTEGER The dimension of the array IWORK. If N <= 1, LIWORK >= 1. If JOBZ = 'N' and N > 1, LIWORK >= 1. If JOBZ = 'V' and N > 1, LIWORK >= 3 + 5*N. If LIWORK = -1, then a workspace query is assumed; the routine only calculates the optimal sizes of the WORK and IWORK arrays, returns these values as the first entries of the WORK and IWORK arrays, and no error message related to LWORK or LIWORK is issued by XERBLA. INFO (output) INTEGER = 0: successful exit < 0: if INFO = -i, the i-th argument had an illegal value > 0: if INFO = i and JOBZ = 'N', then the algorithm failed to converge; i off-diagonal elements of an intermediate tridiagonal form did not converge to zero; if INFO = i and JOBZ = 'V', then the algorithm failed to compute an eigenvalue while working on the submatrix lying in rows and columns INFO/(N+1) through mod(INFO,N+1). Further Details =============== Based on contributions by Jeff Rutter, Computer Science Division, University of California at Berkeley, USA Modified description of INFO. Sven, 16 Feb 05. ===================================================================== */ const char* uplo_ = lapack_uplo_const( uplo ); const char* jobz_ = lapack_vec_const( jobz ); magma_int_t ione = 1; magma_int_t izero = 0; double d_one = 1.; double d__1; double eps; magma_int_t inde; double anrm; double rmin, rmax; double sigma; magma_int_t iinfo, lwmin; magma_int_t lower; magma_int_t wantz; magma_int_t indwk2, llwrk2; magma_int_t iscale; double safmin; double bignum; magma_int_t indtau; magma_int_t indwrk, liwmin; magma_int_t llwork; double smlnum; magma_int_t lquery; magmaDouble_ptr dwork; wantz = (jobz == MagmaVec); lower = (uplo == MagmaLower); lquery = (lwork == -1 || liwork == -1); *info = 0; if (! (wantz || (jobz == MagmaNoVec))) { *info = -1; } else if (! (lower || (uplo == MagmaUpper))) { *info = -2; } else if (n < 0) { *info = -3; } else if (lda < max(1,n)) { *info = -5; } magma_int_t nb = magma_get_dsytrd_nb( n ); if ( n <= 1 ) { lwmin = 1; liwmin = 1; } else if ( wantz ) { lwmin = max( 2*n + n*nb, 1 + 6*n + 2*n*n ); liwmin = 3 + 5*n; } else { lwmin = 2*n + n*nb; liwmin = 1; } // multiply by 1+eps to ensure length gets rounded up, // if it cannot be exactly represented in floating point. double one_eps = 1. + lapackf77_dlamch("Epsilon"); work[0] = lwmin * one_eps; iwork[0] = liwmin; if ((lwork < lwmin) && !lquery) { *info = -8; } else if ((liwork < liwmin) && ! lquery) { *info = -10; } if (*info != 0) { magma_xerbla( __func__, -(*info) ); return *info; } else if (lquery) { return *info; } /* Quick return if possible */ if (n == 0) { return *info; } if (n == 1) { w[0] = a[0]; if (wantz) { a[0] = 1.; } return *info; } /* Check if matrix is very small then just call LAPACK on CPU, no need for GPU */ if (n <= 128) { #ifdef ENABLE_DEBUG printf("--------------------------------------------------------------\n"); printf(" warning matrix too small N=%d NB=%d, calling lapack on CPU \n", (int) n, (int) nb); printf("--------------------------------------------------------------\n"); #endif lapackf77_dsyevd(jobz_, uplo_, &n, a, &lda, w, work, &lwork, iwork, &liwork, info); return *info; } /* Get machine constants. */ safmin = lapackf77_dlamch("Safe minimum"); eps = lapackf77_dlamch("Precision"); smlnum = safmin / eps; bignum = 1. / smlnum; rmin = magma_dsqrt(smlnum); rmax = magma_dsqrt(bignum); /* Scale matrix to allowable range, if necessary. */ anrm = lapackf77_dlansy("M", uplo_, &n, a, &lda, work ); iscale = 0; if (anrm > 0. && anrm < rmin) { iscale = 1; sigma = rmin / anrm; } else if (anrm > rmax) { iscale = 1; sigma = rmax / anrm; } if (iscale == 1) { lapackf77_dlascl(uplo_, &izero, &izero, &d_one, &sigma, &n, &n, a, &lda, info); } /* Call DSYTRD to reduce symmetric matrix to tridiagonal form. */ // dsytrd work: e (n) + tau (n) + llwork (n*nb) ==> 2n + n*nb // dstedx work: e (n) + tau (n) + z (n*n) + llwrk2 (1 + 4*n + n^2) ==> 1 + 6n + 2n^2 inde = 0; indtau = inde + n; indwrk = indtau + n; indwk2 = indwrk + n*n; llwork = lwork - indwrk; llwrk2 = lwork - indwk2; magma_timer_t time; timer_start( time ); magma_dsytrd(uplo, n, a, lda, w, &work[inde], &work[indtau], &work[indwrk], llwork, queue, &iinfo); timer_stop( time ); timer_printf( "time dsytrd = %6.2f\n", time ); /* For eigenvalues only, call DSTERF. For eigenvectors, first call DSTEDC to generate the eigenvector matrix, WORK(INDWRK), of the tridiagonal matrix, then call DORMTR to multiply it to the Householder transformations represented as Householder vectors in A. */ if (! wantz) { lapackf77_dsterf(&n, w, &work[inde], info); } else { timer_start( time ); if (MAGMA_SUCCESS != magma_dmalloc( &dwork, 3*n*(n/2 + 1) )) { *info = MAGMA_ERR_DEVICE_ALLOC; return *info; } // TTT Possible bug for n < 128 magma_dstedx(MagmaRangeAll, n, 0., 0., 0, 0, w, &work[inde], &work[indwrk], n, &work[indwk2], llwrk2, iwork, liwork, dwork, queue, info); magma_free( dwork ); timer_stop( time ); timer_printf( "time dstedx = %6.2f\n", time ); timer_start( time ); magma_dormtr(MagmaLeft, uplo, MagmaNoTrans, n, n, a, lda, &work[indtau], &work[indwrk], n, &work[indwk2], llwrk2, queue, &iinfo); lapackf77_dlacpy("A", &n, &n, &work[indwrk], &n, a, &lda); timer_stop( time ); timer_printf( "time dormtr + copy = %6.2f\n", time ); } /* If matrix was scaled, then rescale eigenvalues appropriately. */ if (iscale == 1) { d__1 = 1. / sigma; blasf77_dscal(&n, &d__1, w, &ione); } work[0] = lwmin * one_eps; // round up iwork[0] = liwmin; return *info; } /* magma_dsyevd */
/** Purpose ------- ZHEEVDX computes selected eigenvalues and, optionally, eigenvectors of a complex Hermitian matrix A. Eigenvalues and eigenvectors can be selected by specifying either a range of values or a range of indices for the desired eigenvalues. If eigenvectors are desired, it uses a divide and conquer algorithm. The divide and conquer algorithm makes very mild assumptions about floating point arithmetic. It will work on machines with a guard digit in add/subtract, or on those binary machines without guard digits which subtract like the Cray X-MP, Cray Y-MP, Cray C-90, or Cray-2. It could conceivably fail on hexadecimal or decimal machines without guard digits, but we know of none. Arguments --------- @param[in] jobz magma_vec_t - = MagmaNoVec: Compute eigenvalues only; - = MagmaVec: Compute eigenvalues and eigenvectors. @param[in] range magma_range_t - = MagmaRangeAll: all eigenvalues will be found. - = MagmaRangeV: all eigenvalues in the half-open interval (VL,VU] will be found. - = MagmaRangeI: the IL-th through IU-th eigenvalues will be found. @param[in] uplo magma_uplo_t - = MagmaUpper: Upper triangle of A is stored; - = MagmaLower: Lower triangle of A is stored. @param[in] n INTEGER The order of the matrix A. N >= 0. @param[in,out] A COMPLEX_16 array, dimension (LDA, N) On entry, the Hermitian matrix A. If UPLO = MagmaUpper, the leading N-by-N upper triangular part of A contains the upper triangular part of the matrix A. If UPLO = MagmaLower, the leading N-by-N lower triangular part of A contains the lower triangular part of the matrix A. On exit, if JOBZ = MagmaVec, then if INFO = 0, the first m columns of A contains the required orthonormal eigenvectors of the matrix A. If JOBZ = MagmaNoVec, then on exit the lower triangle (if UPLO=MagmaLower) or the upper triangle (if UPLO=MagmaUpper) of A, including the diagonal, is destroyed. @param[in] lda INTEGER The leading dimension of the array A. LDA >= max(1,N). @param[in] vl DOUBLE PRECISION @param[in] vu DOUBLE PRECISION If RANGE=MagmaRangeV, the lower and upper bounds of the interval to be searched for eigenvalues. VL < VU. Not referenced if RANGE = MagmaRangeAll or MagmaRangeI. @param[in] il INTEGER @param[in] iu INTEGER If RANGE=MagmaRangeI, the indices (in ascending order) of the smallest and largest eigenvalues to be returned. 1 <= IL <= IU <= N, if N > 0; IL = 1 and IU = 0 if N = 0. Not referenced if RANGE = MagmaRangeAll or MagmaRangeV. @param[out] m INTEGER The total number of eigenvalues found. 0 <= M <= N. If RANGE = MagmaRangeAll, M = N, and if RANGE = MagmaRangeI, M = IU-IL+1. @param[out] w DOUBLE PRECISION array, dimension (N) If INFO = 0, the required m eigenvalues in ascending order. @param[out] work (workspace) COMPLEX_16 array, dimension (MAX(1,LWORK)) On exit, if INFO = 0, WORK[0] returns the optimal LWORK. @param[in] lwork INTEGER The length of the array WORK. If N <= 1, LWORK >= 1. If JOBZ = MagmaNoVec and N > 1, LWORK >= N + N*NB. If JOBZ = MagmaVec and N > 1, LWORK >= max( N + N*NB, 2*N + N**2 ). NB can be obtained through magma_get_zhetrd_nb(N). \n If LWORK = -1, then a workspace query is assumed; the routine only calculates the optimal sizes of the WORK, RWORK and IWORK arrays, returns these values as the first entries of the WORK, RWORK and IWORK arrays, and no error message related to LWORK or LRWORK or LIWORK is issued by XERBLA. @param[out] rwork (workspace) DOUBLE PRECISION array, dimension (LRWORK) On exit, if INFO = 0, RWORK[0] returns the optimal LRWORK. @param[in] lrwork INTEGER The dimension of the array RWORK. If N <= 1, LRWORK >= 1. If JOBZ = MagmaNoVec and N > 1, LRWORK >= N. If JOBZ = MagmaVec and N > 1, LRWORK >= 1 + 5*N + 2*N**2. \n If LRWORK = -1, then a workspace query is assumed; the routine only calculates the optimal sizes of the WORK, RWORK and IWORK arrays, returns these values as the first entries of the WORK, RWORK and IWORK arrays, and no error message related to LWORK or LRWORK or LIWORK is issued by XERBLA. @param[out] iwork (workspace) INTEGER array, dimension (MAX(1,LIWORK)) On exit, if INFO = 0, IWORK[0] returns the optimal LIWORK. @param[in] liwork INTEGER The dimension of the array IWORK. If N <= 1, LIWORK >= 1. If JOBZ = MagmaNoVec and N > 1, LIWORK >= 1. If JOBZ = MagmaVec and N > 1, LIWORK >= 3 + 5*N. \n If LIWORK = -1, then a workspace query is assumed; the routine only calculates the optimal sizes of the WORK, RWORK and IWORK arrays, returns these values as the first entries of the WORK, RWORK and IWORK arrays, and no error message related to LWORK or LRWORK or LIWORK is issued by XERBLA. @param[out] info INTEGER - = 0: successful exit - < 0: if INFO = -i, the i-th argument had an illegal value - > 0: if INFO = i and JOBZ = MagmaNoVec, then the algorithm failed to converge; i off-diagonal elements of an intermediate tridiagonal form did not converge to zero; if INFO = i and JOBZ = MagmaVec, then the algorithm failed to compute an eigenvalue while working on the submatrix lying in rows and columns INFO/(N+1) through mod(INFO,N+1). Further Details --------------- Based on contributions by Jeff Rutter, Computer Science Division, University of California at Berkeley, USA Modified description of INFO. Sven, 16 Feb 05. @ingroup magma_zheev_driver ********************************************************************/ extern "C" magma_int_t magma_zheevdx( magma_vec_t jobz, magma_range_t range, magma_uplo_t uplo, magma_int_t n, magmaDoubleComplex *A, magma_int_t lda, double vl, double vu, magma_int_t il, magma_int_t iu, magma_int_t *m, double *w, magmaDoubleComplex *work, magma_int_t lwork, #ifdef COMPLEX double *rwork, magma_int_t lrwork, #endif magma_int_t *iwork, magma_int_t liwork, magma_int_t *info) { const char* uplo_ = lapack_uplo_const( uplo ); const char* jobz_ = lapack_vec_const( jobz ); magma_int_t ione = 1; magma_int_t izero = 0; double d_one = 1.; double d__1; double eps; magma_int_t inde; double anrm; magma_int_t imax; double rmin, rmax; double sigma; magma_int_t iinfo, lwmin; magma_int_t lower; magma_int_t llrwk; magma_int_t wantz; magma_int_t indwk2, llwrk2; magma_int_t iscale; double safmin; double bignum; magma_int_t indtau; magma_int_t indrwk, indwrk, liwmin; magma_int_t lrwmin, llwork; double smlnum; magma_int_t lquery; magma_int_t alleig, valeig, indeig; double* dwork; wantz = (jobz == MagmaVec); lower = (uplo == MagmaLower); alleig = (range == MagmaRangeAll); valeig = (range == MagmaRangeV); indeig = (range == MagmaRangeI); lquery = (lwork == -1 || lrwork == -1 || liwork == -1); *info = 0; if (! (wantz || (jobz == MagmaNoVec))) { *info = -1; } else if (! (alleig || valeig || indeig)) { *info = -2; } else if (! (lower || (uplo == MagmaUpper))) { *info = -3; } else if (n < 0) { *info = -4; } else if (lda < max(1,n)) { *info = -6; } else { if (valeig) { if (n > 0 && vu <= vl) { *info = -8; } } else if (indeig) { if (il < 1 || il > max(1,n)) { *info = -9; } else if (iu < min(n,il) || iu > n) { *info = -10; } } } magma_int_t nb = magma_get_zhetrd_nb( n ); if ( n <= 1 ) { lwmin = 1; lrwmin = 1; liwmin = 1; } else if ( wantz ) { lwmin = max( n + n*nb, 2*n + n*n ); lrwmin = 1 + 5*n + 2*n*n; liwmin = 3 + 5*n; } else { lwmin = n + n*nb; lrwmin = n; liwmin = 1; } // multiply by 1+eps (in Double!) to ensure length gets rounded up, // if it cannot be exactly represented in floating point. real_Double_t one_eps = 1. + lapackf77_dlamch("Epsilon"); work[0] = MAGMA_Z_MAKE( lwmin * one_eps, 0.); rwork[0] = lrwmin * one_eps; iwork[0] = liwmin; if ((lwork < lwmin) && !lquery) { *info = -14; } else if ((lrwork < lrwmin) && ! lquery) { *info = -16; } else if ((liwork < liwmin) && ! lquery) { *info = -18; } if (*info != 0) { magma_xerbla( __func__, -(*info) ); return *info; } else if (lquery) { return *info; } /* Quick return if possible */ if (n == 0) { return *info; } if (n == 1) { w[0] = MAGMA_Z_REAL(A[0]); if (wantz) { A[0] = MAGMA_Z_ONE; } return *info; } /* Check if matrix is very small then just call LAPACK on CPU, no need for GPU */ if (n <= 128) { #ifdef ENABLE_DEBUG printf("--------------------------------------------------------------\n"); printf(" warning matrix too small N=%d NB=%d, calling lapack on CPU \n", (int) n, (int) nb); printf("--------------------------------------------------------------\n"); #endif lapackf77_zheevd(jobz_, uplo_, &n, A, &lda, w, work, &lwork, #if defined(PRECISION_z) || defined(PRECISION_c) rwork, &lrwork, #endif iwork, &liwork, info); return *info; } /* Get machine constants. */ safmin = lapackf77_dlamch("Safe minimum"); eps = lapackf77_dlamch("Precision"); smlnum = safmin / eps; bignum = 1. / smlnum; rmin = magma_dsqrt(smlnum); rmax = magma_dsqrt(bignum); /* Scale matrix to allowable range, if necessary. */ anrm = lapackf77_zlanhe("M", uplo_, &n, A, &lda, rwork); iscale = 0; if (anrm > 0. && anrm < rmin) { iscale = 1; sigma = rmin / anrm; } else if (anrm > rmax) { iscale = 1; sigma = rmax / anrm; } if (iscale == 1) { lapackf77_zlascl(uplo_, &izero, &izero, &d_one, &sigma, &n, &n, A, &lda, info); } /* Call ZHETRD to reduce Hermitian matrix to tridiagonal form. */ // zhetrd rwork: e (n) // zstedx rwork: e (n) + llrwk (1 + 4*N + 2*N**2) ==> 1 + 5n + 2n^2 inde = 0; indrwk = inde + n; llrwk = lrwork - indrwk; // zhetrd work: tau (n) + llwork (n*nb) ==> n + n*nb // zstedx work: tau (n) + z (n^2) // zunmtr work: tau (n) + z (n^2) + llwrk2 (n or n*nb) ==> 2n + n^2, or n + n*nb + n^2 indtau = 0; indwrk = indtau + n; indwk2 = indwrk + n*n; llwork = lwork - indwrk; llwrk2 = lwork - indwk2; magma_timer_t time=0; timer_start( time ); magma_zhetrd(uplo, n, A, lda, w, &rwork[inde], &work[indtau], &work[indwrk], llwork, &iinfo); timer_stop( time ); timer_printf( "time zhetrd = %6.2f\n", time ); /* For eigenvalues only, call DSTERF. For eigenvectors, first call ZSTEDC to generate the eigenvector matrix, WORK(INDWRK), of the tridiagonal matrix, then call ZUNMTR to multiply it to the Householder transformations represented as Householder vectors in A. */ if (! wantz) { lapackf77_dsterf(&n, w, &rwork[inde], info); magma_dmove_eig(range, n, w, &il, &iu, vl, vu, m); } else { timer_start( time ); if (MAGMA_SUCCESS != magma_dmalloc( &dwork, 3*n*(n/2 + 1) )) { *info = MAGMA_ERR_DEVICE_ALLOC; return *info; } magma_zstedx(range, n, vl, vu, il, iu, w, &rwork[inde], &work[indwrk], n, &rwork[indrwk], llrwk, iwork, liwork, dwork, info); magma_free( dwork ); timer_stop( time ); timer_printf( "time zstedx = %6.2f\n", time ); timer_start( time ); magma_dmove_eig(range, n, w, &il, &iu, vl, vu, m); magma_zunmtr(MagmaLeft, uplo, MagmaNoTrans, n, *m, A, lda, &work[indtau], &work[indwrk + n * (il-1) ], n, &work[indwk2], llwrk2, &iinfo); lapackf77_zlacpy("A", &n, m, &work[indwrk + n * (il-1)], &n, A, &lda); timer_stop( time ); timer_printf( "time zunmtr + copy = %6.2f\n", time ); } /* If matrix was scaled, then rescale eigenvalues appropriately. */ if (iscale == 1) { if (*info == 0) { imax = n; } else { imax = *info - 1; } d__1 = 1. / sigma; blasf77_dscal(&imax, &d__1, w, &ione); } work[0] = MAGMA_Z_MAKE( lwmin * one_eps, 0.); // round up rwork[0] = lrwmin * one_eps; iwork[0] = liwmin; return *info; } /* magma_zheevdx */
extern "C" magma_int_t magma_zheevdx(char jobz, char range, char uplo, magma_int_t n, magmaDoubleComplex *a, magma_int_t lda, double vl, double vu, magma_int_t il, magma_int_t iu, magma_int_t *m, double *w, magmaDoubleComplex *work, magma_int_t lwork, double *rwork, magma_int_t lrwork, magma_int_t *iwork, magma_int_t liwork, magma_int_t *info) { /* -- MAGMA (version 1.4.1) -- Univ. of Tennessee, Knoxville Univ. of California, Berkeley Univ. of Colorado, Denver December 2013 Purpose ======= ZHEEVDX computes selected eigenvalues and, optionally, eigenvectors of a complex Hermitian matrix A. Eigenvalues and eigenvectors can be selected by specifying either a range of values or a range of indices for the desired eigenvalues. If eigenvectors are desired, it uses a divide and conquer algorithm. The divide and conquer algorithm makes very mild assumptions about floating point arithmetic. It will work on machines with a guard digit in add/subtract, or on those binary machines without guard digits which subtract like the Cray X-MP, Cray Y-MP, Cray C-90, or Cray-2. It could conceivably fail on hexadecimal or decimal machines without guard digits, but we know of none. Arguments ========= JOBZ (input) CHARACTER*1 = 'N': Compute eigenvalues only; = 'V': Compute eigenvalues and eigenvectors. RANGE (input) CHARACTER*1 = 'A': all eigenvalues will be found. = 'V': all eigenvalues in the half-open interval (VL,VU] will be found. = 'I': the IL-th through IU-th eigenvalues will be found. UPLO (input) CHARACTER*1 = 'U': Upper triangle of A is stored; = 'L': Lower triangle of A is stored. N (input) INTEGER The order of the matrix A. N >= 0. A (input/output) COMPLEX_16 array, dimension (LDA, N) On entry, the Hermitian matrix A. If UPLO = 'U', the leading N-by-N upper triangular part of A contains the upper triangular part of the matrix A. If UPLO = 'L', the leading N-by-N lower triangular part of A contains the lower triangular part of the matrix A. On exit, if JOBZ = 'V', then if INFO = 0, the first m columns of A contains the required orthonormal eigenvectors of the matrix A. If JOBZ = 'N', then on exit the lower triangle (if UPLO='L') or the upper triangle (if UPLO='U') of A, including the diagonal, is destroyed. LDA (input) INTEGER The leading dimension of the array A. LDA >= max(1,N). VL (input) DOUBLE PRECISION VU (input) DOUBLE PRECISION If RANGE='V', the lower and upper bounds of the interval to be searched for eigenvalues. VL < VU. Not referenced if RANGE = 'A' or 'I'. IL (input) INTEGER IU (input) INTEGER If RANGE='I', the indices (in ascending order) of the smallest and largest eigenvalues to be returned. 1 <= IL <= IU <= N, if N > 0; IL = 1 and IU = 0 if N = 0. Not referenced if RANGE = 'A' or 'V'. M (output) INTEGER The total number of eigenvalues found. 0 <= M <= N. If RANGE = 'A', M = N, and if RANGE = 'I', M = IU-IL+1. W (output) DOUBLE PRECISION array, dimension (N) If INFO = 0, the required m eigenvalues in ascending order. WORK (workspace/output) COMPLEX_16 array, dimension (MAX(1,LWORK)) On exit, if INFO = 0, WORK[0] returns the optimal LWORK. LWORK (input) INTEGER The length of the array WORK. If N <= 1, LWORK >= 1. If JOBZ = 'N' and N > 1, LWORK >= N + N*NB. If JOBZ = 'V' and N > 1, LWORK >= max( N + N*NB, 2*N + N**2 ). NB can be obtained through magma_get_zhetrd_nb(N). If LWORK = -1, then a workspace query is assumed; the routine only calculates the optimal sizes of the WORK, RWORK and IWORK arrays, returns these values as the first entries of the WORK, RWORK and IWORK arrays, and no error message related to LWORK or LRWORK or LIWORK is issued by XERBLA. RWORK (workspace/output) DOUBLE PRECISION array, dimension (LRWORK) On exit, if INFO = 0, RWORK[0] returns the optimal LRWORK. LRWORK (input) INTEGER The dimension of the array RWORK. If N <= 1, LRWORK >= 1. If JOBZ = 'N' and N > 1, LRWORK >= N. If JOBZ = 'V' and N > 1, LRWORK >= 1 + 5*N + 2*N**2. If LRWORK = -1, then a workspace query is assumed; the routine only calculates the optimal sizes of the WORK, RWORK and IWORK arrays, returns these values as the first entries of the WORK, RWORK and IWORK arrays, and no error message related to LWORK or LRWORK or LIWORK is issued by XERBLA. IWORK (workspace/output) INTEGER array, dimension (MAX(1,LIWORK)) On exit, if INFO = 0, IWORK[0] returns the optimal LIWORK. LIWORK (input) INTEGER The dimension of the array IWORK. If N <= 1, LIWORK >= 1. If JOBZ = 'N' and N > 1, LIWORK >= 1. If JOBZ = 'V' and N > 1, LIWORK >= 3 + 5*N. If LIWORK = -1, then a workspace query is assumed; the routine only calculates the optimal sizes of the WORK, RWORK and IWORK arrays, returns these values as the first entries of the WORK, RWORK and IWORK arrays, and no error message related to LWORK or LRWORK or LIWORK is issued by XERBLA. INFO (output) INTEGER = 0: successful exit < 0: if INFO = -i, the i-th argument had an illegal value > 0: if INFO = i and JOBZ = 'N', then the algorithm failed to converge; i off-diagonal elements of an intermediate tridiagonal form did not converge to zero; if INFO = i and JOBZ = 'V', then the algorithm failed to compute an eigenvalue while working on the submatrix lying in rows and columns INFO/(N+1) through mod(INFO,N+1). Further Details =============== Based on contributions by Jeff Rutter, Computer Science Division, University of California at Berkeley, USA Modified description of INFO. Sven, 16 Feb 05. ===================================================================== */ char uplo_[2] = {uplo, 0}; char jobz_[2] = {jobz, 0}; char range_[2] = {range, 0}; magma_int_t ione = 1; magma_int_t izero = 0; double d_one = 1.; double d__1; double eps; magma_int_t inde; double anrm; magma_int_t imax; double rmin, rmax; double sigma; magma_int_t iinfo, lwmin; magma_int_t lower; magma_int_t llrwk; magma_int_t wantz; magma_int_t indwk2, llwrk2; magma_int_t iscale; double safmin; double bignum; magma_int_t indtau; magma_int_t indrwk, indwrk, liwmin; magma_int_t lrwmin, llwork; double smlnum; magma_int_t lquery; magma_int_t alleig, valeig, indeig; double* dwork; wantz = lapackf77_lsame(jobz_, MagmaVecStr); lower = lapackf77_lsame(uplo_, MagmaLowerStr); alleig = lapackf77_lsame( range_, "A" ); valeig = lapackf77_lsame( range_, "V" ); indeig = lapackf77_lsame( range_, "I" ); lquery = lwork == -1 || lrwork == -1 || liwork == -1; *info = 0; if (! (wantz || lapackf77_lsame(jobz_, MagmaNoVecStr))) { *info = -1; } else if (! (alleig || valeig || indeig)) { *info = -2; } else if (! (lower || lapackf77_lsame(uplo_, MagmaUpperStr))) { *info = -3; } else if (n < 0) { *info = -4; } else if (lda < max(1,n)) { *info = -6; } else { if (valeig) { if (n > 0 && vu <= vl) { *info = -8; } } else if (indeig) { if (il < 1 || il > max(1,n)) { *info = -9; } else if (iu < min(n,il) || iu > n) { *info = -10; } } } magma_int_t nb = magma_get_zhetrd_nb( n ); if ( n <= 1 ) { lwmin = 1; lrwmin = 1; liwmin = 1; } else if ( wantz ) { lwmin = max( n + n*nb, 2*n + n*n ); lrwmin = 1 + 5*n + 2*n*n; liwmin = 3 + 5*n; } else { lwmin = n + n*nb; lrwmin = n; liwmin = 1; } // multiply by 1+eps to ensure length gets rounded up, // if it cannot be exactly represented in floating point. work[0] = MAGMA_Z_MAKE( lwmin * (1. + lapackf77_dlamch("Epsilon")), 0.); rwork[0] = lrwmin * (1. + lapackf77_dlamch("Epsilon")); iwork[0] = liwmin; if ((lwork < lwmin) && !lquery) { *info = -14; } else if ((lrwork < lrwmin) && ! lquery) { *info = -16; } else if ((liwork < liwmin) && ! lquery) { *info = -18; } if (*info != 0) { magma_xerbla( __func__, -(*info) ); return *info; } else if (lquery) { return *info; } /* Quick return if possible */ if (n == 0) { return *info; } if (n == 1) { w[0] = MAGMA_Z_REAL(a[0]); if (wantz) { a[0] = MAGMA_Z_ONE; } return *info; } /* Check if matrix is very small then just call LAPACK on CPU, no need for GPU */ if (n <= 128){ #ifdef ENABLE_DEBUG printf("--------------------------------------------------------------\n"); printf(" warning matrix too small N=%d NB=%d, calling lapack on CPU \n", (int) n, (int) nb); printf("--------------------------------------------------------------\n"); #endif lapackf77_zheevd(jobz_, uplo_, &n, a, &lda, w, work, &lwork, #if defined(PRECISION_z) || defined(PRECISION_c) rwork, &lrwork, #endif iwork, &liwork, info); return *info; } /* Get machine constants. */ safmin = lapackf77_dlamch("Safe minimum"); eps = lapackf77_dlamch("Precision"); smlnum = safmin / eps; bignum = 1. / smlnum; rmin = magma_dsqrt(smlnum); rmax = magma_dsqrt(bignum); /* Scale matrix to allowable range, if necessary. */ anrm = lapackf77_zlanhe("M", uplo_, &n, a, &lda, rwork); iscale = 0; if (anrm > 0. && anrm < rmin) { iscale = 1; sigma = rmin / anrm; } else if (anrm > rmax) { iscale = 1; sigma = rmax / anrm; } if (iscale == 1) { lapackf77_zlascl(uplo_, &izero, &izero, &d_one, &sigma, &n, &n, a, &lda, info); } /* Call ZHETRD to reduce Hermitian matrix to tridiagonal form. */ // zhetrd rwork: e (n) // zstedx rwork: e (n) + llrwk (1 + 4*N + 2*N**2) ==> 1 + 5n + 2n^2 inde = 0; indrwk = inde + n; llrwk = lrwork - indrwk; // zhetrd work: tau (n) + llwork (n*nb) ==> n + n*nb // zstedx work: tau (n) + z (n^2) // zunmtr work: tau (n) + z (n^2) + llwrk2 (n or n*nb) ==> 2n + n^2, or n + n*nb + n^2 indtau = 0; indwrk = indtau + n; indwk2 = indwrk + n*n; llwork = lwork - indwrk; llwrk2 = lwork - indwk2; // #ifdef ENABLE_TIMER magma_timestr_t start, end; start = get_current_time(); #endif magma_zhetrd(uplo_[0], n, a, lda, w, &rwork[inde], &work[indtau], &work[indwrk], llwork, &iinfo); #ifdef ENABLE_TIMER end = get_current_time(); printf("time zhetrd = %6.2f\n", GetTimerValue(start,end)/1000.); #endif /* For eigenvalues only, call DSTERF. For eigenvectors, first call ZSTEDC to generate the eigenvector matrix, WORK(INDWRK), of the tridiagonal matrix, then call ZUNMTR to multiply it to the Householder transformations represented as Householder vectors in A. */ if (! wantz) { lapackf77_dsterf(&n, w, &rwork[inde], info); magma_dmove_eig(range, n, w, &il, &iu, vl, vu, m); } else { #ifdef ENABLE_TIMER start = get_current_time(); #endif if (MAGMA_SUCCESS != magma_dmalloc( &dwork, 3*n*(n/2 + 1) )) { *info = MAGMA_ERR_DEVICE_ALLOC; return *info; } magma_zstedx(range, n, vl, vu, il, iu, w, &rwork[inde], &work[indwrk], n, &rwork[indrwk], llrwk, iwork, liwork, dwork, info); magma_free( dwork ); #ifdef ENABLE_TIMER end = get_current_time(); printf("time zstedx = %6.2f\n", GetTimerValue(start,end)/1000.); start = get_current_time(); #endif magma_dmove_eig(range, n, w, &il, &iu, vl, vu, m); magma_zunmtr(MagmaLeft, uplo, MagmaNoTrans, n, *m, a, lda, &work[indtau], &work[indwrk + n * (il-1) ], n, &work[indwk2], llwrk2, &iinfo); lapackf77_zlacpy("A", &n, m, &work[indwrk + n * (il-1)] , &n, a, &lda); #ifdef ENABLE_TIMER end = get_current_time(); printf("time zunmtr + copy = %6.2f\n", GetTimerValue(start,end)/1000.); #endif } /* If matrix was scaled, then rescale eigenvalues appropriately. */ if (iscale == 1) { if (*info == 0) { imax = n; } else { imax = *info - 1; } d__1 = 1. / sigma; blasf77_dscal(&imax, &d__1, w, &ione); } work[0] = MAGMA_Z_MAKE( lwmin * (1. + lapackf77_dlamch("Epsilon")), 0.); // round up rwork[0] = lrwmin * (1. + lapackf77_dlamch("Epsilon")); iwork[0] = liwmin; return *info; } /* magma_zheevdx */
/** Purpose ------- ZHEEVDX_GPU computes selected eigenvalues and, optionally, eigenvectors of a complex Hermitian matrix A. Eigenvalues and eigenvectors can be selected by specifying either a range of values or a range of indices for the desired eigenvalues. If eigenvectors are desired, it uses a divide and conquer algorithm. The divide and conquer algorithm makes very mild assumptions about floating point arithmetic. It will work on machines with a guard digit in add/subtract, or on those binary machines without guard digits which subtract like the Cray X-MP, Cray Y-MP, Cray C-90, or Cray-2. It could conceivably fail on hexadecimal or decimal machines without guard digits, but we know of none. Arguments --------- @param[in] jobz magma_vec_t - = MagmaNoVec: Compute eigenvalues only; - = MagmaVec: Compute eigenvalues and eigenvectors. @param[in] range magma_range_t - = MagmaRangeAll: all eigenvalues will be found. - = MagmaRangeV: all eigenvalues in the half-open interval (VL,VU] will be found. - = MagmaRangeI: the IL-th through IU-th eigenvalues will be found. @param[in] uplo magma_uplo_t - = MagmaUpper: Upper triangle of A is stored; - = MagmaLower: Lower triangle of A is stored. @param[in] n INTEGER The order of the matrix A. N >= 0. @param[in,out] dA COMPLEX_16 array on the GPU, dimension (LDDA, N). On entry, the Hermitian matrix A. If UPLO = MagmaUpper, the leading N-by-N upper triangular part of A contains the upper triangular part of the matrix A. If UPLO = MagmaLower, the leading N-by-N lower triangular part of A contains the lower triangular part of the matrix A. On exit, if JOBZ = MagmaVec, then if INFO = 0, the first mout columns of A contains the required orthonormal eigenvectors of the matrix A. If JOBZ = MagmaNoVec, then on exit the lower triangle (if UPLO=MagmaLower) or the upper triangle (if UPLO=MagmaUpper) of A, including the diagonal, is destroyed. @param[in] ldda INTEGER The leading dimension of the array DA. LDDA >= max(1,N). @param[in] vl DOUBLE PRECISION @param[in] vu DOUBLE PRECISION If RANGE=MagmaRangeV, the lower and upper bounds of the interval to be searched for eigenvalues. VL < VU. Not referenced if RANGE = MagmaRangeAll or MagmaRangeI. @param[in] il INTEGER @param[in] iu INTEGER If RANGE=MagmaRangeI, the indices (in ascending order) of the smallest and largest eigenvalues to be returned. 1 <= IL <= IU <= N, if N > 0; IL = 1 and IU = 0 if N = 0. Not referenced if RANGE = MagmaRangeAll or MagmaRangeV. @param[out] mout INTEGER The total number of eigenvalues found. 0 <= MOUT <= N. If RANGE = MagmaRangeAll, MOUT = N, and if RANGE = MagmaRangeI, MOUT = IU-IL+1. @param[out] w DOUBLE PRECISION array, dimension (N) If INFO = 0, the required mout eigenvalues in ascending order. @param wA (workspace) COMPLEX_16 array, dimension (LDWA, N) @param[in] ldwa INTEGER The leading dimension of the array wA. LDWA >= max(1,N). @param[out] work (workspace) COMPLEX_16 array, dimension (MAX(1,LWORK)) On exit, if INFO = 0, WORK[0] returns the optimal LWORK. @param[in] lwork INTEGER The length of the array WORK. If N <= 1, LWORK >= 1. If JOBZ = MagmaNoVec and N > 1, LWORK >= N + N*NB. If JOBZ = MagmaVec and N > 1, LWORK >= max( N + N*NB, 2*N + N**2 ). NB can be obtained through magma_get_zhetrd_nb(N). \n If LWORK = -1, then a workspace query is assumed; the routine only calculates the optimal sizes of the WORK, RWORK and IWORK arrays, returns these values as the first entries of the WORK, RWORK and IWORK arrays, and no error message related to LWORK or LRWORK or LIWORK is issued by XERBLA. @param[out] rwork (workspace) DOUBLE PRECISION array, dimension (LRWORK) On exit, if INFO = 0, RWORK[0] returns the optimal LRWORK. @param[in] lrwork INTEGER The dimension of the array RWORK. If N <= 1, LRWORK >= 1. If JOBZ = MagmaNoVec and N > 1, LRWORK >= N. If JOBZ = MagmaVec and N > 1, LRWORK >= 1 + 5*N + 2*N**2. \n If LRWORK = -1, then a workspace query is assumed; the routine only calculates the optimal sizes of the WORK, RWORK and IWORK arrays, returns these values as the first entries of the WORK, RWORK and IWORK arrays, and no error message related to LWORK or LRWORK or LIWORK is issued by XERBLA. @param[out] iwork (workspace) INTEGER array, dimension (MAX(1,LIWORK)) On exit, if INFO = 0, IWORK[0] returns the optimal LIWORK. @param[in] liwork INTEGER The dimension of the array IWORK. If N <= 1, LIWORK >= 1. If JOBZ = MagmaNoVec and N > 1, LIWORK >= 1. If JOBZ = MagmaVec and N > 1, LIWORK >= 3 + 5*N. \n If LIWORK = -1, then a workspace query is assumed; the routine only calculates the optimal sizes of the WORK, RWORK and IWORK arrays, returns these values as the first entries of the WORK, RWORK and IWORK arrays, and no error message related to LWORK or LRWORK or LIWORK is issued by XERBLA. @param[out] info INTEGER - = 0: successful exit - < 0: if INFO = -i, the i-th argument had an illegal value - > 0: if INFO = i and JOBZ = MagmaNoVec, then the algorithm failed to converge; i off-diagonal elements of an intermediate tridiagonal form did not converge to zero; if INFO = i and JOBZ = MagmaVec, then the algorithm failed to compute an eigenvalue while working on the submatrix lying in rows and columns INFO/(N+1) through mod(INFO,N+1). Further Details --------------- Based on contributions by Jeff Rutter, Computer Science Division, University of California at Berkeley, USA Modified description of INFO. Sven, 16 Feb 05. @ingroup magma_zheev_driver ********************************************************************/ extern "C" magma_int_t magma_zheevdx_gpu( magma_vec_t jobz, magma_range_t range, magma_uplo_t uplo, magma_int_t n, magmaDoubleComplex_ptr dA, magma_int_t ldda, double vl, double vu, magma_int_t il, magma_int_t iu, magma_int_t *mout, double *w, magmaDoubleComplex *wA, magma_int_t ldwa, magmaDoubleComplex *work, magma_int_t lwork, #ifdef COMPLEX double *rwork, magma_int_t lrwork, #endif magma_int_t *iwork, magma_int_t liwork, magma_int_t *info) { const char* uplo_ = lapack_uplo_const( uplo ); const char* jobz_ = lapack_vec_const( jobz ); magma_int_t ione = 1; double d__1; double eps; magma_int_t inde; double anrm; magma_int_t imax; double rmin, rmax; double sigma; magma_int_t iinfo, lwmin; magma_int_t lower; magma_int_t llrwk; magma_int_t wantz; //magma_int_t indwk2; magma_int_t iscale; double safmin; double bignum; magma_int_t indtau; magma_int_t indrwk, indwrk, liwmin; magma_int_t lrwmin, llwork; double smlnum; magma_int_t lquery; magma_int_t alleig, valeig, indeig; magmaDouble_ptr dwork; magmaDoubleComplex_ptr dC; magma_int_t lddc = ldda; wantz = (jobz == MagmaVec); lower = (uplo == MagmaLower); alleig = (range == MagmaRangeAll); valeig = (range == MagmaRangeV); indeig = (range == MagmaRangeI); lquery = (lwork == -1 || lrwork == -1 || liwork == -1); *info = 0; if (! (wantz || (jobz == MagmaNoVec))) { *info = -1; } else if (! (alleig || valeig || indeig)) { *info = -2; } else if (! (lower || (uplo == MagmaUpper))) { *info = -3; } else if (n < 0) { *info = -4; } else if (ldda < max(1,n)) { *info = -6; } else if (ldwa < max(1,n)) { *info = -14; } else { if (valeig) { if (n > 0 && vu <= vl) { *info = -8; } } else if (indeig) { if (il < 1 || il > max(1,n)) { *info = -9; } else if (iu < min(n,il) || iu > n) { *info = -10; } } } magma_int_t nb = magma_get_zhetrd_nb( n ); if ( n <= 1 ) { lwmin = 1; lrwmin = 1; liwmin = 1; } else if ( wantz ) { lwmin = max( n + n*nb, 2*n + n*n ); lrwmin = 1 + 5*n + 2*n*n; liwmin = 3 + 5*n; } else { lwmin = n + n*nb; lrwmin = n; liwmin = 1; } // multiply by 1+eps (in Double!) to ensure length gets rounded up, // if it cannot be exactly represented in floating point. real_Double_t one_eps = 1. + lapackf77_dlamch("Epsilon"); work[0] = MAGMA_Z_MAKE( lwmin * one_eps, 0 ); rwork[0] = lrwmin * one_eps; iwork[0] = liwmin; if ((lwork < lwmin) && !lquery) { *info = -16; } else if ((lrwork < lrwmin) && ! lquery) { *info = -18; } else if ((liwork < liwmin) && ! lquery) { *info = -20; } if (*info != 0) { magma_xerbla( __func__, -(*info) ); return *info; } else if (lquery) { return *info; } /* If matrix is very small, then just call LAPACK on CPU, no need for GPU */ if (n <= 128) { magma_int_t lda = n; magmaDoubleComplex *A; magma_zmalloc_cpu( &A, lda*n ); magma_zgetmatrix( n, n, dA, ldda, A, lda ); lapackf77_zheevd( jobz_, uplo_, &n, A, &lda, w, work, &lwork, rwork, &lrwork, iwork, &liwork, info ); magma_zsetmatrix( n, n, A, lda, dA, ldda ); magma_free_cpu( A ); *mout = n; return *info; } magma_queue_t stream; magma_queue_create( &stream ); // dC and dwork are never used together, so use one buffer for both; // unfortunately they're different types (complex and double). // (this is easier in dsyevd_gpu where everything is double.) // zhetrd2_gpu requires ldda*ceildiv(n,64) + 2*ldda*nb, in double-complex. // zunmtr_gpu requires lddc*n, in double-complex. // zlanhe requires n, in double. magma_int_t ldwork = max( ldda*ceildiv(n,64) + 2*ldda*nb, lddc*n ); magma_int_t ldwork_real = max( ldwork*2, n ); if ( wantz ) { // zstedx requrise 3n^2/2, in double ldwork_real = max( ldwork_real, 3*n*(n/2 + 1) ); } if (MAGMA_SUCCESS != magma_dmalloc( &dwork, ldwork_real )) { *info = MAGMA_ERR_DEVICE_ALLOC; return *info; } dC = (magmaDoubleComplex*) dwork; /* Get machine constants. */ safmin = lapackf77_dlamch("Safe minimum"); eps = lapackf77_dlamch("Precision"); smlnum = safmin / eps; bignum = 1. / smlnum; rmin = magma_dsqrt( smlnum ); rmax = magma_dsqrt( bignum ); /* Scale matrix to allowable range, if necessary. */ anrm = magmablas_zlanhe( MagmaMaxNorm, uplo, n, dA, ldda, dwork ); iscale = 0; sigma = 1; if (anrm > 0. && anrm < rmin) { iscale = 1; sigma = rmin / anrm; } else if (anrm > rmax) { iscale = 1; sigma = rmax / anrm; } if (iscale == 1) { magmablas_zlascl( uplo, 0, 0, 1., sigma, n, n, dA, ldda, info ); } /* Call ZHETRD to reduce Hermitian matrix to tridiagonal form. */ // zhetrd rwork: e (n) // zstedx rwork: e (n) + llrwk (1 + 4*N + 2*N**2) ==> 1 + 5n + 2n^2 inde = 0; indrwk = inde + n; llrwk = lrwork - indrwk; // zhetrd work: tau (n) + llwork (n*nb) ==> n + n*nb // zstedx work: tau (n) + z (n^2) // zunmtr work: tau (n) + z (n^2) + llwrk2 (n or n*nb) ==> 2n + n^2, or n + n*nb + n^2 indtau = 0; indwrk = indtau + n; //indwk2 = indwrk + n*n; llwork = lwork - indwrk; //llwrk2 = lwork - indwk2; magma_timer_t time=0; timer_start( time ); #ifdef FAST_HEMV magma_zhetrd2_gpu( uplo, n, dA, ldda, w, &rwork[inde], &work[indtau], wA, ldwa, &work[indwrk], llwork, dC, ldwork, &iinfo ); #else magma_zhetrd_gpu ( uplo, n, dA, ldda, w, &rwork[inde], &work[indtau], wA, ldwa, &work[indwrk], llwork, &iinfo ); #endif timer_stop( time ); timer_printf( "time zhetrd_gpu = %6.2f\n", time ); /* For eigenvalues only, call DSTERF. For eigenvectors, first call ZSTEDC to generate the eigenvector matrix, WORK(INDWRK), of the tridiagonal matrix, then call ZUNMTR to multiply it to the Householder transformations represented as Householder vectors in A. */ if (! wantz) { lapackf77_dsterf( &n, w, &rwork[inde], info ); magma_dmove_eig( range, n, w, &il, &iu, vl, vu, mout ); } else { timer_start( time ); magma_zstedx( range, n, vl, vu, il, iu, w, &rwork[inde], &work[indwrk], n, &rwork[indrwk], llrwk, iwork, liwork, dwork, info ); timer_stop( time ); timer_printf( "time zstedx = %6.2f\n", time ); timer_start( time ); magma_dmove_eig( range, n, w, &il, &iu, vl, vu, mout ); magma_zsetmatrix( n, *mout, &work[indwrk + n * (il-1) ], n, dC, lddc ); magma_zunmtr_gpu( MagmaLeft, uplo, MagmaNoTrans, n, *mout, dA, ldda, &work[indtau], dC, lddc, wA, ldwa, &iinfo ); magma_zcopymatrix( n, *mout, dC, lddc, dA, ldda ); timer_stop( time ); timer_printf( "time zunmtr_gpu + copy = %6.2f\n", time ); } /* If matrix was scaled, then rescale eigenvalues appropriately. */ if (iscale == 1) { if (*info == 0) { imax = n; } else { imax = *info - 1; } d__1 = 1. / sigma; blasf77_dscal( &imax, &d__1, w, &ione ); } work[0] = MAGMA_Z_MAKE( lwmin * one_eps, 0 ); // round up rwork[0] = lrwmin * one_eps; iwork[0] = liwmin; magma_queue_destroy( stream ); magma_free( dwork ); return *info; } /* magma_zheevdx_gpu */
/** Purpose ------- ZHEEVR computes selected eigenvalues and, optionally, eigenvectors of a complex Hermitian matrix T. Eigenvalues and eigenvectors can be selected by specifying either a range of values or a range of indices for the desired eigenvalues. Whenever possible, ZHEEVR calls ZSTEGR to compute the eigenspectrum using Relatively Robust Representations. ZSTEGR computes eigenvalues by the dqds algorithm, while orthogonal eigenvectors are computed from various "good" L D L^T representations (also known as Relatively Robust Representations). Gram-Schmidt orthogonalization is avoided as far as possible. More specifically, the various steps of the algorithm are as follows. For the i-th unreduced block of T, 1. Compute T - sigma_i = L_i D_i L_i^T, such that L_i D_i L_i^T is a relatively robust representation, 2. Compute the eigenvalues, lambda_j, of L_i D_i L_i^T to high relative accuracy by the dqds algorithm, 3. If there is a cluster of close eigenvalues, "choose" sigma_i close to the cluster, and go to step (a), 4. Given the approximate eigenvalue lambda_j of L_i D_i L_i^T, compute the corresponding eigenvector by forming a rank-revealing twisted factorization. The desired accuracy of the output can be specified by the input parameter ABSTOL. For more details, see "A new O(n^2) algorithm for the symmetric tridiagonal eigenvalue/eigenvector problem", by Inderjit Dhillon, Computer Science Division Technical Report No. UCB//CSD-97-971, UC Berkeley, May 1997. Note 1 : ZHEEVR calls ZSTEGR when the full spectrum is requested on machines which conform to the ieee-754 floating point standard. ZHEEVR calls DSTEBZ and ZSTEIN on non-ieee machines and when partial spectrum requests are made. Normal execution of ZSTEGR may create NaNs and infinities and hence may abort due to a floating point exception in environments which do not handle NaNs and infinities in the ieee standard default manner. Arguments --------- @param[in] jobz magma_vec_t - = MagmaNoVec: Compute eigenvalues only; - = MagmaVec: Compute eigenvalues and eigenvectors. @param[in] range magma_range_t - = MagmaRangeAll: all eigenvalues will be found. - = MagmaRangeV: all eigenvalues in the half-open interval (VL,VU] will be found. - = MagmaRangeI: the IL-th through IU-th eigenvalues will be found. @param[in] uplo magma_uplo_t - = MagmaUpper: Upper triangle of A is stored; - = MagmaLower: Lower triangle of A is stored. @param[in] n INTEGER The order of the matrix A. N >= 0. @param[in,out] A COMPLEX_16 array, dimension (LDA, N) On entry, the Hermitian matrix A. If UPLO = MagmaUpper, the leading N-by-N upper triangular part of A contains the upper triangular part of the matrix A. If UPLO = MagmaLower, the leading N-by-N lower triangular part of A contains the lower triangular part of the matrix A. On exit, the lower triangle (if UPLO=MagmaLower) or the upper triangle (if UPLO=MagmaUpper) of A, including the diagonal, is destroyed. @param[in] lda INTEGER The leading dimension of the array A. LDA >= max(1,N). @param[in] vl DOUBLE PRECISION @param[in] vu DOUBLE PRECISION If RANGE=MagmaRangeV, the lower and upper bounds of the interval to be searched for eigenvalues. VL < VU. Not referenced if RANGE = MagmaRangeAll or MagmaRangeI. @param[in] il INTEGER @param[in] iu INTEGER If RANGE=MagmaRangeI, the indices (in ascending order) of the smallest and largest eigenvalues to be returned. 1 <= IL <= IU <= N, if N > 0; IL = 1 and IU = 0 if N = 0. Not referenced if RANGE = MagmaRangeAll or MagmaRangeV. @param[in] abstol DOUBLE PRECISION The absolute error tolerance for the eigenvalues. An approximate eigenvalue is accepted as converged when it is determined to lie in an interval [a,b] of width less than or equal to ABSTOL + EPS * max( |a|,|b| ), \n where EPS is the machine precision. If ABSTOL is less than or equal to zero, then EPS*|T| will be used in its place, where |T| is the 1-norm of the tridiagonal matrix obtained by reducing A to tridiagonal form. \n See "Computing Small Singular Values of Bidiagonal Matrices with Guaranteed High Relative Accuracy," by Demmel and Kahan, LAPACK Working Note #3. \n If high relative accuracy is important, set ABSTOL to DLAMCH( 'Safe minimum' ). Doing so will guarantee that eigenvalues are computed to high relative accuracy when possible in future releases. The current code does not make any guarantees about high relative accuracy, but furutre releases will. See J. Barlow and J. Demmel, "Computing Accurate Eigensystems of Scaled Diagonally Dominant Matrices", LAPACK Working Note #7, for a discussion of which matrices define their eigenvalues to high relative accuracy. @param[out] m INTEGER The total number of eigenvalues found. 0 <= M <= N. If RANGE = MagmaRangeAll, M = N, and if RANGE = MagmaRangeI, M = IU-IL+1. @param[out] w DOUBLE PRECISION array, dimension (N) The first M elements contain the selected eigenvalues in ascending order. @param[out] Z COMPLEX_16 array, dimension (LDZ, max(1,M)) If JOBZ = MagmaVec, then if INFO = 0, the first M columns of Z contain the orthonormal eigenvectors of the matrix A corresponding to the selected eigenvalues, with the i-th column of Z holding the eigenvector associated with W(i). If JOBZ = MagmaNoVec, then Z is not referenced. Note: the user must ensure that at least max(1,M) columns are supplied in the array Z; if RANGE = MagmaRangeV, the exact value of M is not known in advance and an upper bound must be used. @param[in] ldz INTEGER The leading dimension of the array Z. LDZ >= 1, and if JOBZ = MagmaVec, LDZ >= max(1,N). @param[out] isuppz INTEGER ARRAY, dimension ( 2*max(1,M) ) The support of the eigenvectors in Z, i.e., the indices indicating the nonzero elements in Z. The i-th eigenvector is nonzero only in elements ISUPPZ( 2*i-1 ) through ISUPPZ( 2*i ). __Implemented only for__ RANGE = MagmaRangeAll or MagmaRangeI and IU - IL = N - 1 @param[out] work (workspace) COMPLEX_16 array, dimension (LWORK) On exit, if INFO = 0, WORK[0] returns the optimal LWORK. @param[in] lwork INTEGER The length of the array WORK. LWORK >= max(1,2*N). For optimal efficiency, LWORK >= (NB+1)*N, where NB is the max of the blocksize for ZHETRD and for ZUNMTR as returned by ILAENV. \n If LWORK = -1, then a workspace query is assumed; the routine only calculates the optimal size of the WORK array, returns this value as the first entry of the WORK array, and no error message related to LWORK is issued by XERBLA. @param[out] rwork (workspace) DOUBLE PRECISION array, dimension (LRWORK) On exit, if INFO = 0, RWORK[0] returns the optimal (and minimal) LRWORK. @param[in] lrwork INTEGER The length of the array RWORK. LRWORK >= max(1,24*N). \n If LRWORK = -1, then a workspace query is assumed; the routine only calculates the optimal size of the RWORK array, returns this value as the first entry of the RWORK array, and no error message related to LRWORK is issued by XERBLA. @param[out] iwork (workspace) INTEGER array, dimension (LIWORK) On exit, if INFO = 0, IWORK[0] returns the optimal (and minimal) LIWORK. @param[in] liwork INTEGER The dimension of the array IWORK. LIWORK >= max(1,10*N). \n If LIWORK = -1, then a workspace query is assumed; the routine only calculates the optimal size of the IWORK array, returns this value as the first entry of the IWORK array, and no error message related to LIWORK is issued by XERBLA. @param[out] info INTEGER - = 0: successful exit - < 0: if INFO = -i, the i-th argument had an illegal value - > 0: Internal error Further Details --------------- Based on contributions by Inderjit Dhillon, IBM Almaden, USA Osni Marques, LBNL/NERSC, USA Ken Stanley, Computer Science Division, University of California at Berkeley, USA @ingroup magma_zheev_driver ********************************************************************/ extern "C" magma_int_t magma_zheevr( magma_vec_t jobz, magma_range_t range, magma_uplo_t uplo, magma_int_t n, magmaDoubleComplex *A, magma_int_t lda, double vl, double vu, magma_int_t il, magma_int_t iu, double abstol, magma_int_t *m, double *w, magmaDoubleComplex *Z, magma_int_t ldz, magma_int_t *isuppz, magmaDoubleComplex *work, magma_int_t lwork, double *rwork, magma_int_t lrwork, magma_int_t *iwork, magma_int_t liwork, magma_int_t *info) { /* Constants */ const magma_int_t izero = 0; const magma_int_t ione = 1; const float szero = 0.; const float sone = 1.; /* Local variables */ const char* uplo_ = lapack_uplo_const( uplo ); const char* jobz_ = lapack_vec_const( jobz ); const char* range_ = lapack_range_const( range ); magma_int_t indrd, indre; magma_int_t imax; magma_int_t lopt, itmp1, indree, indrdd; magma_int_t tryrac; magma_int_t i, j, jj, i__1; magma_int_t iscale, indibl, indifl; magma_int_t indiwo, indisp, indtau; magma_int_t indrwk, indwk; magma_int_t llwork, llrwork, nsplit; magma_int_t ieeeok; magma_int_t iinfo; magma_int_t lwmin, lrwmin, liwmin; double safmin; double bignum; double smlnum; double eps, tmp1; double anrm; double sigma, d__1; double rmin, rmax; bool lower = (uplo == MagmaLower); bool wantz = (jobz == MagmaVec); bool alleig = (range == MagmaRangeAll); bool valeig = (range == MagmaRangeV); bool indeig = (range == MagmaRangeI); bool lquery = (lwork == -1 || lrwork == -1 || liwork == -1); *info = 0; if (! (wantz || (jobz == MagmaNoVec))) { *info = -1; } else if (! (alleig || valeig || indeig)) { *info = -2; } else if (! (lower || (uplo == MagmaUpper))) { *info = -3; } else if (n < 0) { *info = -4; } else if (lda < max(1,n)) { *info = -6; } else if (ldz < 1 || (wantz && ldz < n)) { *info = -15; } else { if (valeig) { if (n > 0 && vu <= vl) { *info = -8; } } else if (indeig) { if (il < 1 || il > max(1,n)) { *info = -9; } else if (iu < min(n,il) || iu > n) { *info = -10; } } } magma_int_t nb = magma_get_zhetrd_nb(n); lwmin = n * (nb + 1); lrwmin = 24 * n; liwmin = 10 * n; work[0] = magma_zmake_lwork( lwmin ); rwork[0] = magma_dmake_lwork( lrwmin ); iwork[0] = liwmin; if (lwork < lwmin && ! lquery) { *info = -18; } else if ((lrwork < lrwmin) && ! lquery) { *info = -20; } else if ((liwork < liwmin) && ! lquery) { *info = -22; } if (*info != 0) { magma_xerbla(__func__, -(*info)); return *info; } else if (lquery) { return *info; } *m = 0; /* Check if matrix is very small then just call LAPACK on CPU, no need for GPU */ if (n <= 128) { #ifdef ENABLE_DEBUG printf("--------------------------------------------------------------\n"); printf(" warning matrix too small N=%d NB=%d, calling lapack on CPU \n", (int) n, (int) nb); printf("--------------------------------------------------------------\n"); #endif lapackf77_zheevr(jobz_, range_, uplo_, &n, A, &lda, &vl, &vu, &il, &iu, &abstol, m, w, Z, &ldz, isuppz, work, &lwork, rwork, &lrwork, iwork, &liwork, info); return *info; } --w; --work; --rwork; --iwork; --isuppz; /* Get machine constants. */ safmin = lapackf77_dlamch("Safe minimum"); eps = lapackf77_dlamch("Precision"); smlnum = safmin / eps; bignum = 1. / smlnum; rmin = magma_dsqrt(smlnum); rmax = magma_dsqrt(bignum); /* Scale matrix to allowable range, if necessary. */ anrm = lapackf77_zlanhe("M", uplo_, &n, A, &lda, &rwork[1]); iscale = 0; if (anrm > 0. && anrm < rmin) { iscale = 1; sigma = rmin / anrm; } else if (anrm > rmax) { iscale = 1; sigma = rmax / anrm; } if (iscale == 1) { d__1 = 1.; lapackf77_zlascl(uplo_, &izero, &izero, &d__1, &sigma, &n, &n, A, &lda, info); if (abstol > 0.) { abstol *= sigma; } if (valeig) { vl *= sigma; vu *= sigma; } } /* Call ZHETRD to reduce Hermitian matrix to tridiagonal form. */ indtau = 1; indwk = indtau + n; indre = 1; indrd = indre + n; indree = indrd + n; indrdd = indree + n; indrwk = indrdd + n; llwork = lwork - indwk + 1; llrwork = lrwork - indrwk + 1; indifl = 1; indibl = indifl + n; indisp = indibl + n; indiwo = indisp + n; magma_zhetrd(uplo, n, A, lda, &rwork[indrd], &rwork[indre], &work[indtau], &work[indwk], llwork, &iinfo); lopt = n + (magma_int_t)MAGMA_Z_REAL(work[indwk]); /* If all eigenvalues are desired and ABSTOL is less than or equal to zero, then call DSTERF or ZUNGTR and ZSTEQR. If this fails for some eigenvalue, then try DSTEBZ. */ ieeeok = lapackf77_ieeeck( &ione, &szero, &sone); /* If only the eigenvalues are required call DSTERF for all or DSTEBZ for a part */ if (! wantz) { blasf77_dcopy(&n, &rwork[indrd], &ione, &w[1], &ione); i__1 = n - 1; if (alleig || (indeig && il == 1 && iu == n)) { lapackf77_dsterf(&n, &w[1], &rwork[indre], info); *m = n; } else { lapackf77_dstebz(range_, "E", &n, &vl, &vu, &il, &iu, &abstol, &rwork[indrd], &rwork[indre], m, &nsplit, &w[1], &iwork[indibl], &iwork[indisp], &rwork[indrwk], &iwork[indiwo], info); } /* Otherwise call ZSTEMR if infinite and NaN arithmetic is supported */ } else if (ieeeok == 1) { i__1 = n - 1; blasf77_dcopy(&i__1, &rwork[indre], &ione, &rwork[indree], &ione); blasf77_dcopy(&n, &rwork[indrd], &ione, &rwork[indrdd], &ione); if (abstol < 2*n*eps) tryrac = 1; else tryrac = 0; lapackf77_zstemr(jobz_, range_, &n, &rwork[indrdd], &rwork[indree], &vl, &vu, &il, &iu, m, &w[1], Z, &ldz, &n, &isuppz[1], &tryrac, &rwork[indrwk], &llrwork, &iwork[1], &liwork, info); if (*info == 0 && wantz) { magma_zunmtr(MagmaLeft, uplo, MagmaNoTrans, n, *m, A, lda, &work[indtau], Z, ldz, &work[indwk], llwork, &iinfo); } } /* Call DSTEBZ and ZSTEIN if infinite and NaN arithmetic is not supported or ZSTEMR didn't converge. */ if (wantz && (ieeeok == 0 || *info != 0)) { *info = 0; lapackf77_dstebz(range_, "B", &n, &vl, &vu, &il, &iu, &abstol, &rwork[indrd], &rwork[indre], m, &nsplit, &w[1], &iwork[indibl], &iwork[indisp], &rwork[indrwk], &iwork[indiwo], info); lapackf77_zstein(&n, &rwork[indrd], &rwork[indre], m, &w[1], &iwork[indibl], &iwork[indisp], Z, &ldz, &rwork[indrwk], &iwork[indiwo], &iwork[indifl], info); /* Apply unitary matrix used in reduction to tridiagonal form to eigenvectors returned by ZSTEIN. */ magma_zunmtr(MagmaLeft, uplo, MagmaNoTrans, n, *m, A, lda, &work[indtau], Z, ldz, &work[indwk], llwork, &iinfo); } /* If matrix was scaled, then rescale eigenvalues appropriately. */ if (iscale == 1) { if (*info == 0) { imax = *m; } else { imax = *info - 1; } d__1 = 1. / sigma; blasf77_dscal(&imax, &d__1, &w[1], &ione); } /* If eigenvalues are not in order, then sort them, along with eigenvectors. */ if (wantz) { for (j = 1; j <= *m-1; ++j) { i = 0; tmp1 = w[j]; for (jj = j + 1; jj <= *m; ++jj) { if (w[jj] < tmp1) { i = jj; tmp1 = w[jj]; } } if (i != 0) { itmp1 = iwork[indibl + i - 1]; w[i] = w[j]; iwork[indibl + i - 1] = iwork[indibl + j - 1]; w[j] = tmp1; iwork[indibl + j - 1] = itmp1; blasf77_zswap(&n, Z + (i-1)*ldz, &ione, Z + (j-1)*ldz, &ione); } } } /* Set WORK[0] to optimal complex workspace size. */ work[1] = magma_zmake_lwork( lopt ); rwork[1] = magma_dmake_lwork( lrwmin ); iwork[1] = liwmin; return *info; } /* magma_zheevr */
/** Purpose ------- DSYEVD_GPU computes all eigenvalues and, optionally, eigenvectors of a real symmetric matrix A. If eigenvectors are desired, it uses a divide and conquer algorithm. The divide and conquer algorithm makes very mild assumptions about floating point arithmetic. It will work on machines with a guard digit in add/subtract, or on those binary machines without guard digits which subtract like the Cray X-MP, Cray Y-MP, Cray C-90, or Cray-2. It could conceivably fail on hexadecimal or decimal machines without guard digits, but we know of none. Arguments --------- @param[in] jobz magma_vec_t - = MagmaNoVec: Compute eigenvalues only; - = MagmaVec: Compute eigenvalues and eigenvectors. @param[in] uplo magma_uplo_t - = MagmaUpper: Upper triangle of A is stored; - = MagmaLower: Lower triangle of A is stored. @param[in] n INTEGER The order of the matrix A. N >= 0. @param[in,out] dA DOUBLE PRECISION array on the GPU, dimension (LDDA, N). On entry, the symmetric matrix A. If UPLO = MagmaUpper, the leading N-by-N upper triangular part of A contains the upper triangular part of the matrix A. If UPLO = MagmaLower, the leading N-by-N lower triangular part of A contains the lower triangular part of the matrix A. On exit, if JOBZ = MagmaVec, then if INFO = 0, A contains the orthonormal eigenvectors of the matrix A. If JOBZ = MagmaNoVec, then on exit the lower triangle (if UPLO=MagmaLower) or the upper triangle (if UPLO=MagmaUpper) of A, including the diagonal, is destroyed. @param[in] ldda INTEGER The leading dimension of the array DA. LDDA >= max(1,N). @param[out] w DOUBLE PRECISION array, dimension (N) If INFO = 0, the eigenvalues in ascending order. @param wA (workspace) DOUBLE PRECISION array, dimension (LDWA, N) @param[in] ldwa INTEGER The leading dimension of the array wA. LDWA >= max(1,N). @param[out] work (workspace) DOUBLE PRECISION array, dimension (MAX(1,LWORK)) On exit, if INFO = 0, WORK[0] returns the optimal LWORK. @param[in] lwork INTEGER The length of the array WORK. If N <= 1, LWORK >= 1. If JOBZ = MagmaNoVec and N > 1, LWORK >= 2*N + N*NB. If JOBZ = MagmaVec and N > 1, LWORK >= max( 2*N + N*NB, 1 + 6*N + 2*N**2 ). NB can be obtained through magma_get_dsytrd_nb(N). \n If LWORK = -1, then a workspace query is assumed; the routine only calculates the optimal sizes of the WORK and IWORK arrays, returns these values as the first entries of the WORK and IWORK arrays, and no error message related to LWORK or LIWORK is issued by XERBLA. @param[out] iwork (workspace) INTEGER array, dimension (MAX(1,LIWORK)) On exit, if INFO = 0, IWORK[0] returns the optimal LIWORK. @param[in] liwork INTEGER The dimension of the array IWORK. If N <= 1, LIWORK >= 1. If JOBZ = MagmaNoVec and N > 1, LIWORK >= 1. If JOBZ = MagmaVec and N > 1, LIWORK >= 3 + 5*N. \n If LIWORK = -1, then a workspace query is assumed; the routine only calculates the optimal sizes of the WORK and IWORK arrays, returns these values as the first entries of the WORK and IWORK arrays, and no error message related to LWORK or LIWORK is issued by XERBLA. @param[out] info INTEGER - = 0: successful exit - < 0: if INFO = -i, the i-th argument had an illegal value - > 0: if INFO = i and JOBZ = MagmaNoVec, then the algorithm failed to converge; i off-diagonal elements of an intermediate tridiagonal form did not converge to zero; if INFO = i and JOBZ = MagmaVec, then the algorithm failed to compute an eigenvalue while working on the submatrix lying in rows and columns INFO/(N+1) through mod(INFO,N+1). Further Details --------------- Based on contributions by Jeff Rutter, Computer Science Division, University of California at Berkeley, USA Modified description of INFO. Sven, 16 Feb 05. @ingroup magma_dsyev_driver ********************************************************************/ extern "C" magma_int_t magma_dsyevd_gpu( magma_vec_t jobz, magma_uplo_t uplo, magma_int_t n, magmaDouble_ptr dA, magma_int_t ldda, double *w, double *wA, magma_int_t ldwa, double *work, magma_int_t lwork, #ifdef COMPLEX double *rwork, magma_int_t lrwork, #endif magma_int_t *iwork, magma_int_t liwork, magma_int_t *info) { magma_int_t ione = 1; double d__1; double eps; magma_int_t inde; double anrm; double rmin, rmax; double sigma; magma_int_t iinfo, lwmin; magma_int_t lower; magma_int_t wantz; magma_int_t indwk2, llwrk2; magma_int_t iscale; double safmin; double bignum; magma_int_t indtau; magma_int_t indwrk, liwmin; magma_int_t llwork; double smlnum; magma_int_t lquery; magmaDouble_ptr dwork; magma_int_t lddc = ldda; wantz = (jobz == MagmaVec); lower = (uplo == MagmaLower); lquery = (lwork == -1 || liwork == -1); *info = 0; if (! (wantz || (jobz == MagmaNoVec))) { *info = -1; } else if (! (lower || (uplo == MagmaUpper))) { *info = -2; } else if (n < 0) { *info = -3; } else if (ldda < max(1,n)) { *info = -5; } magma_int_t nb = magma_get_dsytrd_nb( n ); if ( n <= 1 ) { lwmin = 1; liwmin = 1; } else if ( wantz ) { lwmin = max( 2*n + n*nb, 1 + 6*n + 2*n*n ); liwmin = 3 + 5*n; } else { lwmin = 2*n + n*nb; liwmin = 1; } work[0] = magma_dmake_lwork( lwmin ); iwork[0] = liwmin; if ((lwork < lwmin) && !lquery) { *info = -10; } else if ((liwork < liwmin) && ! lquery) { *info = -12; } if (*info != 0) { magma_xerbla( __func__, -(*info) ); return *info; } else if (lquery) { return *info; } magma_queue_t queue; magma_device_t cdev; magma_getdevice( &cdev ); magma_queue_create( cdev, &queue ); /* If matrix is very small, then just call LAPACK on CPU, no need for GPU */ if (n <= 128) { magma_int_t lda = n; double *A; magma_dmalloc_cpu( &A, lda*n ); magma_dgetmatrix( n, n, dA, ldda, A, lda, queue ); lapackf77_dsyevd( lapack_vec_const(jobz), lapack_uplo_const(uplo), &n, A, &lda, w, work, &lwork, iwork, &liwork, info ); magma_dsetmatrix( n, n, A, lda, dA, ldda, queue ); magma_free_cpu( A ); magma_queue_destroy( queue ); return *info; } // dsytrd2_gpu requires ldda*ceildiv(n,64) + 2*ldda*nb // dormtr_gpu requires lddc*n // dlansy requires n magma_int_t ldwork = max( ldda*magma_ceildiv(n,64) + 2*ldda*nb, lddc*n ); ldwork = max( ldwork, n ); if ( wantz ) { // dstedx requires 3n^2/2 ldwork = max( ldwork, 3*n*(n/2 + 1) ); } if (MAGMA_SUCCESS != magma_dmalloc( &dwork, ldwork )) { *info = MAGMA_ERR_DEVICE_ALLOC; return *info; } /* Get machine constants. */ safmin = lapackf77_dlamch("Safe minimum"); eps = lapackf77_dlamch("Precision"); smlnum = safmin / eps; bignum = 1. / smlnum; rmin = magma_dsqrt( smlnum ); rmax = magma_dsqrt( bignum ); /* Scale matrix to allowable range, if necessary. */ anrm = magmablas_dlansy( MagmaMaxNorm, uplo, n, dA, ldda, dwork, ldwork, queue ); iscale = 0; sigma = 1; if (anrm > 0. && anrm < rmin) { iscale = 1; sigma = rmin / anrm; } else if (anrm > rmax) { iscale = 1; sigma = rmax / anrm; } if (iscale == 1) { magmablas_dlascl( uplo, 0, 0, 1., sigma, n, n, dA, ldda, queue, info ); } /* Call DSYTRD to reduce symmetric matrix to tridiagonal form. */ // dsytrd work: e (n) + tau (n) + llwork (n*nb) ==> 2n + n*nb // dstedx work: e (n) + tau (n) + z (n*n) + llwrk2 (1 + 4*n + n^2) ==> 1 + 6n + 2n^2 inde = 0; indtau = inde + n; indwrk = indtau + n; indwk2 = indwrk + n*n; llwork = lwork - indwrk; llwrk2 = lwork - indwk2; magma_timer_t time=0; timer_start( time ); #ifdef FAST_SYMV magma_dsytrd2_gpu( uplo, n, dA, ldda, w, &work[inde], &work[indtau], wA, ldwa, &work[indwrk], llwork, dwork, ldwork, &iinfo ); #else magma_dsytrd_gpu( uplo, n, dA, ldda, w, &work[inde], &work[indtau], wA, ldwa, &work[indwrk], llwork, &iinfo ); #endif timer_stop( time ); #ifdef FAST_SYMV timer_printf( "time dsytrd2 = %6.2f\n", time ); #else timer_printf( "time dsytrd = %6.2f\n", time ); #endif /* For eigenvalues only, call DSTERF. For eigenvectors, first call DSTEDC to generate the eigenvector matrix, WORK(INDWRK), of the tridiagonal matrix, then call DORMTR to multiply it to the Householder transformations represented as Householder vectors in A. */ if (! wantz) { lapackf77_dsterf( &n, w, &work[inde], info ); } else { timer_start( time ); magma_dstedx( MagmaRangeAll, n, 0., 0., 0, 0, w, &work[inde], &work[indwrk], n, &work[indwk2], llwrk2, iwork, liwork, dwork, info ); timer_stop( time ); timer_printf( "time dstedx = %6.2f\n", time ); timer_start( time ); magma_dsetmatrix( n, n, &work[indwrk], n, dwork, lddc, queue ); magma_dormtr_gpu( MagmaLeft, uplo, MagmaNoTrans, n, n, dA, ldda, &work[indtau], dwork, lddc, wA, ldwa, &iinfo ); magma_dcopymatrix( n, n, dwork, lddc, dA, ldda, queue ); timer_stop( time ); timer_printf( "time dormtr + copy = %6.2f\n", time ); } /* If matrix was scaled, then rescale eigenvalues appropriately. */ if (iscale == 1) { d__1 = 1. / sigma; blasf77_dscal( &n, &d__1, w, &ione ); } work[0] = magma_dmake_lwork( lwmin ); iwork[0] = liwmin; magma_queue_destroy( queue ); magma_free( dwork ); return *info; } /* magma_dsyevd_gpu */
/** Purpose ------- DSYEVDX computes selected eigenvalues and, optionally, eigenvectors of a real symmetric matrix A. Eigenvalues and eigenvectors can be selected by specifying either a range of values or a range of indices for the desired eigenvalues. If eigenvectors are desired, it uses a divide and conquer algorithm. The divide and conquer algorithm makes very mild assumptions about floating point arithmetic. It will work on machines with a guard digit in add/subtract, or on those binary machines without guard digits which subtract like the Cray X-MP, Cray Y-MP, Cray C-90, or Cray-2. It could conceivably fail on hexadecimal or decimal machines without guard digits, but we know of none. Arguments --------- @param[in] jobz magma_vec_t - = MagmaNoVec: Compute eigenvalues only; - = MagmaVec: Compute eigenvalues and eigenvectors. @param[in] range magma_range_t - = MagmaRangeAll: all eigenvalues will be found. - = MagmaRangeV: all eigenvalues in the half-open interval (VL,VU] will be found. - = MagmaRangeI: the IL-th through IU-th eigenvalues will be found. @param[in] uplo magma_uplo_t - = MagmaUpper: Upper triangle of A is stored; - = MagmaLower: Lower triangle of A is stored. @param[in] n INTEGER The order of the matrix A. N >= 0. @param[in,out] dA DOUBLE_PRECISION array on the GPU, dimension (LDDA, N). On entry, the symmetric matrix A. If UPLO = MagmaUpper, the leading N-by-N upper triangular part of A contains the upper triangular part of the matrix A. If UPLO = MagmaLower, the leading N-by-N lower triangular part of A contains the lower triangular part of the matrix A. On exit, if JOBZ = MagmaVec, then if INFO = 0, the first m columns of A contains the required orthonormal eigenvectors of the matrix A. If JOBZ = MagmaNoVec, then on exit the lower triangle (if UPLO=MagmaLower) or the upper triangle (if UPLO=MagmaUpper) of A, including the diagonal, is destroyed. @param[in] ldda INTEGER The leading dimension of the array DA. LDDA >= max(1,N). @param[in] vl DOUBLE PRECISION @param[in] vu DOUBLE PRECISION If RANGE=MagmaRangeV, the lower and upper bounds of the interval to be searched for eigenvalues. VL < VU. Not referenced if RANGE = MagmaRangeAll or MagmaRangeI. @param[in] il INTEGER @param[in] iu INTEGER If RANGE=MagmaRangeI, the indices (in ascending order) of the smallest and largest eigenvalues to be returned. 1 <= IL <= IU <= N, if N > 0; IL = 1 and IU = 0 if N = 0. Not referenced if RANGE = MagmaRangeAll or MagmaRangeV. @param[out] m INTEGER The total number of eigenvalues found. 0 <= M <= N. If RANGE = MagmaRangeAll, M = N, and if RANGE = MagmaRangeI, M = IU-IL+1. @param[out] w DOUBLE PRECISION array, dimension (N) If INFO = 0, the required m eigenvalues in ascending order. @param wA (workspace) DOUBLE PRECISION array, dimension (LDWA, N) @param[in] ldwa INTEGER The leading dimension of the array wA. LDWA >= max(1,N). @param[out] work (workspace) DOUBLE_PRECISION array, dimension (MAX(1,LWORK)) On exit, if INFO = 0, WORK[0] returns the optimal LWORK. @param[in] lwork INTEGER The length of the array WORK. If N <= 1, LWORK >= 1. If JOBZ = MagmaNoVec and N > 1, LWORK >= 2*N + N*NB. If JOBZ = MagmaVec and N > 1, LWORK >= max( 2*N + N*NB, 1 + 6*N + 2*N**2 ). NB can be obtained through magma_get_dsytrd_nb(N). \n If LWORK = -1, then a workspace query is assumed; the routine only calculates the optimal sizes of the WORK and IWORK arrays, returns these values as the first entries of the WORK and IWORK arrays, and no error message related to LWORK or LIWORK is issued by XERBLA. @param[out] iwork (workspace) INTEGER array, dimension (MAX(1,LIWORK)) On exit, if INFO = 0, IWORK[0] returns the optimal LIWORK. @param[in] liwork INTEGER The dimension of the array IWORK. If N <= 1, LIWORK >= 1. If JOBZ = MagmaNoVec and N > 1, LIWORK >= 1. If JOBZ = MagmaVec and N > 1, LIWORK >= 3 + 5*N. \n If LIWORK = -1, then a workspace query is assumed; the routine only calculates the optimal sizes of the WORK and IWORK arrays, returns these values as the first entries of the WORK and IWORK arrays, and no error message related to LWORK or LIWORK is issued by XERBLA. @param[out] info INTEGER - = 0: successful exit - < 0: if INFO = -i, the i-th argument had an illegal value - > 0: if INFO = i and JOBZ = MagmaNoVec, then the algorithm failed to converge; i off-diagonal elements of an intermediate tridiagonal form did not converge to zero; if INFO = i and JOBZ = MagmaVec, then the algorithm failed to compute an eigenvalue while working on the submatrix lying in rows and columns INFO/(N+1) through mod(INFO,N+1). Further Details --------------- Based on contributions by Jeff Rutter, Computer Science Division, University of California at Berkeley, USA Modified description of INFO. Sven, 16 Feb 05. @ingroup magma_dsyev_driver ********************************************************************/ extern "C" magma_int_t magma_dsyevdx_gpu(magma_vec_t jobz, magma_range_t range, magma_uplo_t uplo, magma_int_t n, double *dA, magma_int_t ldda, double vl, double vu, magma_int_t il, magma_int_t iu, magma_int_t *m, double *w, double *wA, magma_int_t ldwa, double *work, magma_int_t lwork, magma_int_t *iwork, magma_int_t liwork, magma_int_t *info) { magma_int_t ione = 1; double d__1; double eps; magma_int_t inde; double anrm; double rmin, rmax; double sigma; magma_int_t iinfo, lwmin; magma_int_t lower; magma_int_t wantz; magma_int_t indwk2, llwrk2; magma_int_t iscale; double safmin; double bignum; magma_int_t indtau; magma_int_t indwrk, liwmin; magma_int_t llwork; double smlnum; magma_int_t lquery; magma_int_t alleig, valeig, indeig; double *dwork; magma_int_t lddc = ldda; wantz = (jobz == MagmaVec); lower = (uplo == MagmaLower); alleig = (range == MagmaRangeAll); valeig = (range == MagmaRangeV); indeig = (range == MagmaRangeI); lquery = (lwork == -1 || liwork == -1); *info = 0; if (! (wantz || (jobz == MagmaNoVec))) { *info = -1; } else if (! (alleig || valeig || indeig)) { *info = -2; } else if (! (lower || (uplo == MagmaUpper))) { *info = -3; } else if (n < 0) { *info = -4; } else if (ldda < max(1,n)) { *info = -6; } else if (ldwa < max(1,n)) { *info = -14; } else { if (valeig) { if (n > 0 && vu <= vl) { *info = -8; } } else if (indeig) { if (il < 1 || il > max(1,n)) { *info = -9; } else if (iu < min(n,il) || iu > n) { *info = -10; } } } magma_int_t nb = magma_get_dsytrd_nb( n ); if ( n <= 1 ) { lwmin = 1; liwmin = 1; } else if ( wantz ) { lwmin = max( 2*n + n*nb, 1 + 6*n + 2*n*n ); liwmin = 3 + 5*n; } else { lwmin = 2*n + n*nb; liwmin = 1; } // multiply by 1+eps (in Double!) to ensure length gets rounded up, // if it cannot be exactly represented in floating point. real_Double_t one_eps = 1. + lapackf77_dlamch("Epsilon"); work[0] = lwmin * one_eps; iwork[0] = liwmin; if ((lwork < lwmin) && !lquery) { *info = -16; } else if ((liwork < liwmin) && ! lquery) { *info = -18; } if (*info != 0) { magma_xerbla( __func__, -(*info) ); return *info; } else if (lquery) { return *info; } /* Check if matrix is very small then just call LAPACK on CPU, no need for GPU */ if (n <= 128) { #ifdef ENABLE_DEBUG printf("--------------------------------------------------------------\n"); printf(" warning matrix too small N=%d NB=%d, calling lapack on CPU \n", (int) n, (int) nb); printf("--------------------------------------------------------------\n"); #endif const char* jobz_ = lapack_vec_const( jobz ); const char* uplo_ = lapack_uplo_const( uplo ); double *A; magma_dmalloc_cpu( &A, n*n ); magma_dgetmatrix(n, n, dA, ldda, A, n); lapackf77_dsyevd(jobz_, uplo_, &n, A, &n, w, work, &lwork, iwork, &liwork, info); magma_dsetmatrix( n, n, A, n, dA, ldda); magma_free_cpu(A); return *info; } magma_queue_t stream; magma_queue_create( &stream ); // n*lddc for dsytrd2_gpu // n for dlansy magma_int_t ldwork = n*lddc; if ( wantz ) { // need 3n^2/2 for dstedx ldwork = max( ldwork, 3*n*(n/2 + 1)); } if (MAGMA_SUCCESS != magma_dmalloc( &dwork, ldwork )) { *info = MAGMA_ERR_DEVICE_ALLOC; return *info; } /* Get machine constants. */ safmin = lapackf77_dlamch("Safe minimum"); eps = lapackf77_dlamch("Precision"); smlnum = safmin / eps; bignum = 1. / smlnum; rmin = magma_dsqrt(smlnum); rmax = magma_dsqrt(bignum); /* Scale matrix to allowable range, if necessary. */ anrm = magmablas_dlansy(MagmaMaxNorm, uplo, n, dA, ldda, dwork); iscale = 0; sigma = 1; if (anrm > 0. && anrm < rmin) { iscale = 1; sigma = rmin / anrm; } else if (anrm > rmax) { iscale = 1; sigma = rmax / anrm; } if (iscale == 1) { magmablas_dlascl(uplo, 0, 0, 1., sigma, n, n, dA, ldda, info); } /* Call DSYTRD to reduce symmetric matrix to tridiagonal form. */ // dsytrd work: e (n) + tau (n) + llwork (n*nb) ==> 2n + n*nb // dstedx work: e (n) + tau (n) + z (n*n) + llwrk2 (1 + 4*n + n^2) ==> 1 + 6n + 2n^2 inde = 0; indtau = inde + n; indwrk = indtau + n; indwk2 = indwrk + n*n; llwork = lwork - indwrk; llwrk2 = lwork - indwk2; magma_timer_t time=0; timer_start( time ); #ifdef FAST_SYMV magma_dsytrd2_gpu(uplo, n, dA, ldda, w, &work[inde], &work[indtau], wA, ldwa, &work[indwrk], llwork, dwork, n*lddc, &iinfo); #else magma_dsytrd_gpu(uplo, n, dA, ldda, w, &work[inde], &work[indtau], wA, ldwa, &work[indwrk], llwork, &iinfo); #endif timer_stop( time ); timer_printf( "time dsytrd = %6.2f\n", time ); /* For eigenvalues only, call DSTERF. For eigenvectors, first call DSTEDC to generate the eigenvector matrix, WORK(INDWRK), of the tridiagonal matrix, then call DORMTR to multiply it to the Householder transformations represented as Householder vectors in A. */ if (! wantz) { lapackf77_dsterf(&n, w, &work[inde], info); magma_dmove_eig(range, n, w, &il, &iu, vl, vu, m); } else { timer_start( time ); magma_dstedx(range, n, vl, vu, il, iu, w, &work[inde], &work[indwrk], n, &work[indwk2], llwrk2, iwork, liwork, dwork, info); timer_stop( time ); timer_printf( "time dstedx = %6.2f\n", time ); timer_start( time ); magma_dmove_eig(range, n, w, &il, &iu, vl, vu, m); magma_dsetmatrix( n, *m, &work[indwrk + n* (il-1) ], n, dwork, lddc ); magma_dormtr_gpu(MagmaLeft, uplo, MagmaNoTrans, n, *m, dA, ldda, &work[indtau], dwork, lddc, wA, ldwa, &iinfo); magma_dcopymatrix( n, *m, dwork, lddc, dA, ldda ); timer_stop( time ); timer_printf( "time dormtr + copy = %6.2f\n", time ); } /* If matrix was scaled, then rescale eigenvalues appropriately. */ if (iscale == 1) { d__1 = 1. / sigma; blasf77_dscal(&n, &d__1, w, &ione); } work[0] = lwmin * one_eps; // round up iwork[0] = liwmin; magma_queue_destroy( stream ); magma_free( dwork ); return *info; } /* magma_dsyevd_gpu */
/** Purpose ------- ZHEEVX computes selected eigenvalues and, optionally, eigenvectors of a complex Hermitian matrix A. Eigenvalues and eigenvectors can be selected by specifying either a range of values or a range of indices for the desired eigenvalues. Arguments --------- @param[in] jobz magma_vec_t - = MagmaNoVec: Compute eigenvalues only; - = MagmaVec: Compute eigenvalues and eigenvectors. @param[in] range magma_range_t - = MagmaRangeAll: all eigenvalues will be found. - = MagmaRangeV: all eigenvalues in the half-open interval (VL,VU] will be found. - = MagmaRangeI: the IL-th through IU-th eigenvalues will be found. @param[in] uplo magma_uplo_t - = MagmaUpper: Upper triangle of A is stored; - = MagmaLower: Lower triangle of A is stored. @param[in] n INTEGER The order of the matrix A. N >= 0. @param[in,out] dA COMPLEX_16 array, dimension (LDDA, N) On entry, the Hermitian matrix A. If UPLO = MagmaUpper, the leading N-by-N upper triangular part of A contains the upper triangular part of the matrix A. If UPLO = MagmaLower, the leading N-by-N lower triangular part of A contains the lower triangular part of the matrix A. On exit, the lower triangle (if UPLO=MagmaLower) or the upper triangle (if UPLO=MagmaUpper) of A, including the diagonal, is destroyed. @param[in] ldda INTEGER The leading dimension of the array DA. LDDA >= max(1,N). @param[in] vl DOUBLE PRECISION @param[in] vu DOUBLE PRECISION If RANGE=MagmaRangeV, the lower and upper bounds of the interval to be searched for eigenvalues. VL < VU. Not referenced if RANGE = MagmaRangeAll or MagmaRangeI. @param[in] il INTEGER @param[in] iu INTEGER If RANGE=MagmaRangeI, the indices (in ascending order) of the smallest and largest eigenvalues to be returned. 1 <= IL <= IU <= N, if N > 0; IL = 1 and IU = 0 if N = 0. Not referenced if RANGE = MagmaRangeAll or MagmaRangeV. @param[in] abstol DOUBLE PRECISION The absolute error tolerance for the eigenvalues. An approximate eigenvalue is accepted as converged when it is determined to lie in an interval [a,b] of width less than or equal to ABSTOL + EPS * max( |a|,|b| ), \n where EPS is the machine precision. If ABSTOL is less than or equal to zero, then EPS*|T| will be used in its place, where |T| is the 1-norm of the tridiagonal matrix obtained by reducing A to tridiagonal form. \n Eigenvalues will be computed most accurately when ABSTOL is set to twice the underflow threshold 2*DLAMCH('S'), not zero. If this routine returns with INFO > 0, indicating that some eigenvectors did not converge, try setting ABSTOL to 2*DLAMCH('S'). \n See "Computing Small Singular Values of Bidiagonal Matrices with Guaranteed High Relative Accuracy," by Demmel and Kahan, LAPACK Working Note #3. @param[out] m INTEGER The total number of eigenvalues found. 0 <= M <= N. If RANGE = MagmaRangeAll, M = N, and if RANGE = MagmaRangeI, M = IU-IL+1. @param[out] w DOUBLE PRECISION array, dimension (N) On normal exit, the first M elements contain the selected eigenvalues in ascending order. @param[out] dZ COMPLEX_16 array, dimension (LDDZ, max(1,M)) If JOBZ = MagmaVec, then if INFO = 0, the first M columns of Z contain the orthonormal eigenvectors of the matrix A corresponding to the selected eigenvalues, with the i-th column of Z holding the eigenvector associated with W(i). If an eigenvector fails to converge, then that column of Z contains the latest approximation to the eigenvector, and the index of the eigenvector is returned in IFAIL. If JOBZ = MagmaNoVec, then Z is not referenced. Note: the user must ensure that at least max(1,M) columns are supplied in the array Z; if RANGE = MagmaRangeV, the exact value of M is not known in advance and an upper bound must be used. ********* (workspace) If FAST_HEMV is defined DZ should be (LDDZ, max(1,N)) in both cases. @param[in] lddz INTEGER The leading dimension of the array DZ. LDDZ >= 1, and if JOBZ = MagmaVec, LDDZ >= max(1,N). @param wA (workspace) COMPLEX_16 array, dimension (LDWA, N) @param[in] ldwa INTEGER The leading dimension of the array wA. LDWA >= max(1,N). @param wZ (workspace) COMPLEX_16 array, dimension (LDWZ, max(1,M)) @param[in] ldwz INTEGER The leading dimension of the array wZ. LDWZ >= 1, and if JOBZ = MagmaVec, LDWZ >= max(1,N). @param[out] work (workspace) COMPLEX_16 array, dimension (LWORK) On exit, if INFO = 0, WORK[0] returns the optimal LWORK. @param[in] lwork INTEGER The length of the array WORK. LWORK >= (NB+1)*N, where NB is the max of the blocksize for ZHETRD. \n If LWORK = -1, then a workspace query is assumed; the routine only calculates the optimal size of the WORK array, returns this value as the first entry of the WORK array, and no error message related to LWORK is issued by XERBLA. @param rwork (workspace) DOUBLE PRECISION array, dimension (7*N) @param iwork (workspace) INTEGER array, dimension (5*N) @param[out] ifail INTEGER array, dimension (N) If JOBZ = MagmaVec, then if INFO = 0, the first M elements of IFAIL are zero. If INFO > 0, then IFAIL contains the indices of the eigenvectors that failed to converge. If JOBZ = MagmaNoVec, then IFAIL is not referenced. @param[out] info INTEGER - = 0: successful exit - < 0: if INFO = -i, the i-th argument had an illegal value - > 0: if INFO = i, then i eigenvectors failed to converge. Their indices are stored in array IFAIL. @ingroup magma_zheev_driver ********************************************************************/ extern "C" magma_int_t magma_zheevx_gpu(magma_vec_t jobz, magma_range_t range, magma_uplo_t uplo, magma_int_t n, magmaDoubleComplex *dA, magma_int_t ldda, double vl, double vu, magma_int_t il, magma_int_t iu, double abstol, magma_int_t *m, double *w, magmaDoubleComplex *dZ, magma_int_t lddz, magmaDoubleComplex *wA, magma_int_t ldwa, magmaDoubleComplex *wZ, magma_int_t ldwz, magmaDoubleComplex *work, magma_int_t lwork, double *rwork, magma_int_t *iwork, magma_int_t *ifail, magma_int_t *info) { const char* uplo_ = lapack_uplo_const( uplo ); const char* jobz_ = lapack_vec_const( jobz ); const char* range_ = lapack_range_const( range ); magma_int_t ione = 1; const char* order_; magma_int_t indd, inde; magma_int_t imax; magma_int_t lopt, itmp1, indee; magma_int_t lower, wantz; magma_int_t i, j, jj, i__1; magma_int_t alleig, valeig, indeig; magma_int_t iscale, indibl; magma_int_t indiwk, indisp, indtau; magma_int_t indrwk, indwrk; magma_int_t llwork, nsplit; magma_int_t lquery; magma_int_t iinfo; double safmin; double bignum; double smlnum; double eps, tmp1; double anrm; double sigma, d__1; double rmin, rmax; double *dwork; /* Function Body */ lower = (uplo == MagmaLower); wantz = (jobz == MagmaVec); alleig = (range == MagmaRangeAll); valeig = (range == MagmaRangeV); indeig = (range == MagmaRangeI); lquery = (lwork == -1); *info = 0; if (! (wantz || (jobz == MagmaNoVec))) { *info = -1; } else if (! (alleig || valeig || indeig)) { *info = -2; } else if (! (lower || (uplo == MagmaUpper))) { *info = -3; } else if (n < 0) { *info = -4; } else if (ldda < max(1,n)) { *info = -6; } else if (lddz < 1 || (wantz && lddz < n)) { *info = -15; } else if (ldwa < max(1,n)) { *info = -17; } else if (ldwz < 1 || (wantz && ldwz < n)) { *info = -19; } else { if (valeig) { if (n > 0 && vu <= vl) { *info = -8; } } else if (indeig) { if (il < 1 || il > max(1,n)) { *info = -9; } else if (iu < min(n,il) || iu > n) { *info = -10; } } } magma_int_t nb = magma_get_zhetrd_nb(n); lopt = n * (nb + 1); work[0] = MAGMA_Z_MAKE( lopt, 0 ); if (lwork < lopt && ! lquery) { *info = -21; } if (*info != 0) { magma_xerbla( __func__, -(*info)); return *info; } else if (lquery) { return *info; } *m = 0; /* Check if matrix is very small then just call LAPACK on CPU, no need for GPU */ if (n <= 128) { #ifdef ENABLE_DEBUG printf("--------------------------------------------------------------\n"); printf(" warning matrix too small N=%d NB=%d, calling lapack on CPU \n", (int) n, (int) nb); printf("--------------------------------------------------------------\n"); #endif magmaDoubleComplex *a; magma_zmalloc_cpu( &a, n*n ); magma_zgetmatrix(n, n, dA, ldda, a, n); lapackf77_zheevx(jobz_, range_, uplo_, &n, a, &n, &vl, &vu, &il, &iu, &abstol, m, w, wZ, &ldwz, work, &lwork, rwork, iwork, ifail, info); magma_zsetmatrix( n, n, a, n, dA, ldda); magma_zsetmatrix( n, *m, wZ, ldwz, dZ, lddz); magma_free_cpu(a); return *info; } if (MAGMA_SUCCESS != magma_dmalloc( &dwork, n )) { fprintf (stderr, "!!!! device memory allocation error (magma_zheevx_gpu)\n"); *info = MAGMA_ERR_DEVICE_ALLOC; return *info; } --w; --work; --rwork; --iwork; --ifail; /* Get machine constants. */ safmin = lapackf77_dlamch("Safe minimum"); eps = lapackf77_dlamch("Precision"); smlnum = safmin / eps; bignum = 1. / smlnum; rmin = magma_dsqrt(smlnum); rmax = magma_dsqrt(bignum); /* Scale matrix to allowable range, if necessary. */ anrm = magmablas_zlanhe(MagmaMaxNorm, uplo, n, dA, ldda, dwork); iscale = 0; sigma = 1; if (anrm > 0. && anrm < rmin) { iscale = 1; sigma = rmin / anrm; } else if (anrm > rmax) { iscale = 1; sigma = rmax / anrm; } if (iscale == 1) { d__1 = 1.; magmablas_zlascl(uplo, 0, 0, 1., sigma, n, n, dA, ldda, info); if (abstol > 0.) { abstol *= sigma; } if (valeig) { vl *= sigma; vu *= sigma; } } /* Call ZHETRD to reduce Hermitian matrix to tridiagonal form. */ indd = 1; inde = indd + n; indrwk = inde + n; indtau = 1; indwrk = indtau + n; llwork = lwork - indwrk + 1; #ifdef FAST_HEMV magma_zhetrd2_gpu(uplo, n, dA, ldda, &rwork[indd], &rwork[inde], &work[indtau], wA, ldwa, &work[indwrk], llwork, dZ, lddz*n, &iinfo); #else magma_zhetrd_gpu (uplo, n, dA, ldda, &rwork[indd], &rwork[inde], &work[indtau], wA, ldwa, &work[indwrk], llwork, &iinfo); #endif lopt = n + (magma_int_t)MAGMA_Z_REAL(work[indwrk]); /* If all eigenvalues are desired and ABSTOL is less than or equal to zero, then call DSTERF or ZUNGTR and ZSTEQR. If this fails for some eigenvalue, then try DSTEBZ. */ if ((alleig || (indeig && il == 1 && iu == n)) && abstol <= 0.) { blasf77_dcopy(&n, &rwork[indd], &ione, &w[1], &ione); indee = indrwk + 2*n; if (! wantz) { i__1 = n - 1; blasf77_dcopy(&i__1, &rwork[inde], &ione, &rwork[indee], &ione); lapackf77_dsterf(&n, &w[1], &rwork[indee], info); } else { lapackf77_zlacpy("A", &n, &n, wA, &ldwa, wZ, &ldwz); lapackf77_zungtr(uplo_, &n, wZ, &ldwz, &work[indtau], &work[indwrk], &llwork, &iinfo); i__1 = n - 1; blasf77_dcopy(&i__1, &rwork[inde], &ione, &rwork[indee], &ione); lapackf77_zsteqr(jobz_, &n, &w[1], &rwork[indee], wZ, &ldwz, &rwork[indrwk], info); if (*info == 0) { for (i = 1; i <= n; ++i) { ifail[i] = 0; } magma_zsetmatrix( n, n, wZ, ldwz, dZ, lddz ); } } if (*info == 0) { *m = n; } } /* Otherwise, call DSTEBZ and, if eigenvectors are desired, ZSTEIN. */ if (*m == 0) { *info = 0; if (wantz) { order_ = "B"; } else { order_ = "E"; } indibl = 1; indisp = indibl + n; indiwk = indisp + n; lapackf77_dstebz(range_, order_, &n, &vl, &vu, &il, &iu, &abstol, &rwork[indd], &rwork[inde], m, &nsplit, &w[1], &iwork[indibl], &iwork[indisp], &rwork[indrwk], &iwork[indiwk], info); if (wantz) { lapackf77_zstein(&n, &rwork[indd], &rwork[inde], m, &w[1], &iwork[indibl], &iwork[indisp], wZ, &ldwz, &rwork[indrwk], &iwork[indiwk], &ifail[1], info); magma_zsetmatrix( n, *m, wZ, ldwz, dZ, lddz ); /* Apply unitary matrix used in reduction to tridiagonal form to eigenvectors returned by ZSTEIN. */ magma_zunmtr_gpu(MagmaLeft, uplo, MagmaNoTrans, n, *m, dA, ldda, &work[indtau], dZ, lddz, wA, ldwa, &iinfo); } } /* If matrix was scaled, then rescale eigenvalues appropriately. */ if (iscale == 1) { if (*info == 0) { imax = *m; } else { imax = *info - 1; } d__1 = 1. / sigma; blasf77_dscal(&imax, &d__1, &w[1], &ione); } /* If eigenvalues are not in order, then sort them, along with eigenvectors. */ if (wantz) { for (j = 1; j <= *m-1; ++j) { i = 0; tmp1 = w[j]; for (jj = j + 1; jj <= *m; ++jj) { if (w[jj] < tmp1) { i = jj; tmp1 = w[jj]; } } if (i != 0) { itmp1 = iwork[indibl + i - 1]; w[i] = w[j]; iwork[indibl + i - 1] = iwork[indibl + j - 1]; w[j] = tmp1; iwork[indibl + j - 1] = itmp1; magma_zswap(n, dZ + (i-1)*lddz, ione, dZ + (j-1)*lddz, ione); if (*info != 0) { itmp1 = ifail[i]; ifail[i] = ifail[j]; ifail[j] = itmp1; } } } } /* Set WORK[0] to optimal complex workspace size. */ work[1] = MAGMA_Z_MAKE( lopt, 0 ); return *info; } /* magma_zheevx_gpu */
/** Purpose ------- ZHEEVD_2STAGE computes all eigenvalues and, optionally, eigenvectors of a complex Hermitian matrix A. It uses a two-stage algorithm for the tridiagonalization. If eigenvectors are desired, it uses a divide and conquer algorithm. The divide and conquer algorithm makes very mild assumptions about floating point arithmetic. It will work on machines with a guard digit in add/subtract, or on those binary machines without guard digits which subtract like the Cray X-MP, Cray Y-MP, Cray C-90, or Cray-2. It could conceivably fail on hexadecimal or decimal machines without guard digits, but we know of none. Arguments --------- @param[in] nrgpu INTEGER Number of GPUs to use. @param[in] jobz magma_vec_t - = MagmaNoVec: Compute eigenvalues only; - = MagmaVec: Compute eigenvalues and eigenvectors. @param[in] range magma_range_t - = MagmaRangeAll: all eigenvalues will be found. - = MagmaRangeV: all eigenvalues in the half-open interval (VL,VU] will be found. - = MagmaRangeI: the IL-th through IU-th eigenvalues will be found. @param[in] uplo magma_uplo_t - = MagmaUpper: Upper triangle of A is stored; - = MagmaLower: Lower triangle of A is stored. @param[in] n INTEGER The order of the matrix A. N >= 0. @param[in,out] A COMPLEX_16 array, dimension (LDA, N) On entry, the Hermitian matrix A. If UPLO = MagmaUpper, the leading N-by-N upper triangular part of A contains the upper triangular part of the matrix A. If UPLO = MagmaLower, the leading N-by-N lower triangular part of A contains the lower triangular part of the matrix A. On exit, if JOBZ = MagmaVec, then if INFO = 0, the first m columns of A contains the required orthonormal eigenvectors of the matrix A. If JOBZ = MagmaNoVec, then on exit the lower triangle (if UPLO=MagmaLower) or the upper triangle (if UPLO=MagmaUpper) of A, including the diagonal, is destroyed. @param[in] lda INTEGER The leading dimension of the array A. LDA >= max(1,N). @param[in] vl DOUBLE PRECISION @param[in] vu DOUBLE PRECISION If RANGE=MagmaRangeV, the lower and upper bounds of the interval to be searched for eigenvalues. VL < VU. Not referenced if RANGE = MagmaRangeAll or MagmaRangeI. @param[in] il INTEGER @param[in] iu INTEGER If RANGE=MagmaRangeI, the indices (in ascending order) of the smallest and largest eigenvalues to be returned. 1 <= IL <= IU <= N, if N > 0; IL = 1 and IU = 0 if N = 0. Not referenced if RANGE = MagmaRangeAll or MagmaRangeV. @param[out] m INTEGER The total number of eigenvalues found. 0 <= M <= N. If RANGE = MagmaRangeAll, M = N, and if RANGE = MagmaRangeI, M = IU-IL+1. @param[out] w DOUBLE PRECISION array, dimension (N) If INFO = 0, the required m eigenvalues in ascending order. @param[out] work (workspace) COMPLEX_16 array, dimension (MAX(1,LWORK)) On exit, if INFO = 0, WORK[0] returns the optimal LWORK. @param[in] lwork INTEGER The length of the array WORK. If N <= 1, LWORK >= 1. If JOBZ = MagmaNoVec and N > 1, LWORK >= LQ2 + N + N*NB. If JOBZ = MagmaVec and N > 1, LWORK >= LQ2 + 2*N + N**2. where LQ2 is the size needed to store the Q2 matrix and is returned by magma_bulge_get_lq2. \n If LWORK = -1, then a workspace query is assumed; the routine only calculates the optimal sizes of the WORK, RWORK and IWORK arrays, returns these values as the first entries of the WORK, RWORK and IWORK arrays, and no error message related to LWORK or LRWORK or LIWORK is issued by XERBLA. @param[out] rwork (workspace) DOUBLE PRECISION array, dimension (LRWORK) On exit, if INFO = 0, RWORK[0] returns the optimal LRWORK. @param[in] lrwork INTEGER The dimension of the array RWORK. If N <= 1, LRWORK >= 1. If JOBZ = MagmaNoVec and N > 1, LRWORK >= N. If JOBZ = MagmaVec and N > 1, LRWORK >= 1 + 5*N + 2*N**2. \n If LRWORK = -1, then a workspace query is assumed; the routine only calculates the optimal sizes of the WORK, RWORK and IWORK arrays, returns these values as the first entries of the WORK, RWORK and IWORK arrays, and no error message related to LWORK or LRWORK or LIWORK is issued by XERBLA. @param[out] iwork (workspace) INTEGER array, dimension (MAX(1,LIWORK)) On exit, if INFO = 0, IWORK[0] returns the optimal LIWORK. @param[in] liwork INTEGER The dimension of the array IWORK. If N <= 1, LIWORK >= 1. If JOBZ = MagmaNoVec and N > 1, LIWORK >= 1. If JOBZ = MagmaVec and N > 1, LIWORK >= 3 + 5*N. \n If LIWORK = -1, then a workspace query is assumed; the routine only calculates the optimal sizes of the WORK, RWORK and IWORK arrays, returns these values as the first entries of the WORK, RWORK and IWORK arrays, and no error message related to LWORK or LRWORK or LIWORK is issued by XERBLA. @param[out] info INTEGER - = 0: successful exit - < 0: if INFO = -i, the i-th argument had an illegal value - > 0: if INFO = i and JOBZ = MagmaNoVec, then the algorithm failed to converge; i off-diagonal elements of an intermediate tridiagonal form did not converge to zero; if INFO = i and JOBZ = MagmaVec, then the algorithm failed to compute an eigenvalue while working on the submatrix lying in rows and columns INFO/(N+1) through mod(INFO,N+1). Further Details --------------- Based on contributions by Jeff Rutter, Computer Science Division, University of California at Berkeley, USA Modified description of INFO. Sven, 16 Feb 05. @ingroup magma_zheev_driver ********************************************************************/ extern "C" magma_int_t magma_zheevdx_2stage_m(magma_int_t nrgpu, magma_vec_t jobz, magma_range_t range, magma_uplo_t uplo, magma_int_t n, magmaDoubleComplex *A, magma_int_t lda, double vl, double vu, magma_int_t il, magma_int_t iu, magma_int_t *m, double *w, magmaDoubleComplex *work, magma_int_t lwork, double *rwork, magma_int_t lrwork, magma_int_t *iwork, magma_int_t liwork, magma_int_t *info) { #define A( i_,j_) (A + (i_) + (j_)*lda) #define A2(i_,j_) (A2 + (i_) + (j_)*lda2) const char* uplo_ = lapack_uplo_const( uplo ); const char* jobz_ = lapack_vec_const( jobz ); magmaDoubleComplex c_one = MAGMA_Z_ONE; double d_one = 1.; magma_int_t ione = 1; magma_int_t izero = 0; double d__1; double eps; double anrm; magma_int_t imax; double rmin, rmax; double sigma; //magma_int_t iinfo; magma_int_t lwmin, lrwmin, liwmin; magma_int_t lower; magma_int_t wantz; magma_int_t iscale; double safmin; double bignum; double smlnum; magma_int_t lquery; magma_int_t alleig, valeig, indeig; magma_int_t len; /* determine the number of threads */ magma_int_t parallel_threads = magma_get_parallel_numthreads(); wantz = (jobz == MagmaVec); lower = (uplo == MagmaLower); alleig = (range == MagmaRangeAll); valeig = (range == MagmaRangeV); indeig = (range == MagmaRangeI); lquery = (lwork == -1 || lrwork == -1 || liwork == -1); *info = 0; if (! (wantz || (jobz == MagmaNoVec))) { *info = -1; } else if (! (alleig || valeig || indeig)) { *info = -2; } else if (! (lower || (uplo == MagmaUpper))) { *info = -3; } else if (n < 0) { *info = -4; } else if (lda < max(1,n)) { *info = -6; } else { if (valeig) { if (n > 0 && vu <= vl) { *info = -8; } } else if (indeig) { if (il < 1 || il > max(1,n)) { *info = -9; } else if (iu < min(n,il) || iu > n) { *info = -10; } } } magma_int_t nb = magma_get_zbulge_nb(n, parallel_threads); magma_int_t Vblksiz = magma_zbulge_get_Vblksiz(n, nb, parallel_threads); magma_int_t ldt = Vblksiz; magma_int_t ldv = nb + Vblksiz; magma_int_t blkcnt = magma_bulge_get_blkcnt(n, nb, Vblksiz); magma_int_t lq2 = magma_zbulge_get_lq2(n, parallel_threads); if (wantz) { lwmin = lq2 + 2*n + n*n; lrwmin = 1 + 5*n + 2*n*n; liwmin = 5*n + 3; } else { lwmin = lq2 + n + n*nb; lrwmin = n; liwmin = 1; } // multiply by 1+eps (in Double!) to ensure length gets rounded up, // if it cannot be exactly represented in floating point. real_Double_t one_eps = 1. + lapackf77_dlamch("Epsilon"); work[0] = MAGMA_Z_MAKE( lwmin * one_eps, 0.); // round up rwork[0] = lrwmin * one_eps; iwork[0] = liwmin; if ((lwork < lwmin) && !lquery) { *info = -14; } else if ((lrwork < lrwmin) && ! lquery) { *info = -16; } else if ((liwork < liwmin) && ! lquery) { *info = -18; } if (*info != 0) { magma_xerbla( __func__, -(*info) ); return *info; } else if (lquery) { return *info; } /* Quick return if possible */ if (n == 0) { return *info; } if (n == 1) { w[0] = MAGMA_Z_REAL(A[0]); if (wantz) { A[0] = MAGMA_Z_ONE; } return *info; } magma_device_t orig_dev; magma_getdevice( &orig_dev ); timer_printf("using %d parallel_threads\n", (int) parallel_threads); /* Check if matrix is very small then just call LAPACK on CPU, no need for GPU */ magma_int_t ntiles = n/nb; if ( ( ntiles < 2 ) || ( n <= 128 ) ) { #ifdef ENABLE_DEBUG printf("--------------------------------------------------------------\n"); printf(" warning matrix too small N=%d NB=%d, calling lapack on CPU \n", (int) n, (int) nb); printf("--------------------------------------------------------------\n"); #endif lapackf77_zheevd(jobz_, uplo_, &n, A, &lda, w, work, &lwork, #if defined(PRECISION_z) || defined(PRECISION_c) rwork, &lrwork, #endif iwork, &liwork, info); *m = n; return *info; } /* Get machine constants. */ safmin = lapackf77_dlamch("Safe minimum"); eps = lapackf77_dlamch("Precision"); smlnum = safmin / eps; bignum = 1. / smlnum; rmin = magma_dsqrt(smlnum); rmax = magma_dsqrt(bignum); /* Scale matrix to allowable range, if necessary. */ anrm = lapackf77_zlanhe("M", uplo_, &n, A, &lda, rwork); iscale = 0; if (anrm > 0. && anrm < rmin) { iscale = 1; sigma = rmin / anrm; } else if (anrm > rmax) { iscale = 1; sigma = rmax / anrm; } if (iscale == 1) { lapackf77_zlascl(uplo_, &izero, &izero, &d_one, &sigma, &n, &n, A, &lda, info); } magma_int_t indT2 = 0; magma_int_t indTAU2 = indT2 + blkcnt*ldt*Vblksiz; magma_int_t indV2 = indTAU2+ blkcnt*Vblksiz; magma_int_t indtau1 = indV2 + blkcnt*ldv*Vblksiz; magma_int_t indwrk = indtau1+ n; magma_int_t indwk2 = indwrk + n*n; magma_int_t llwork = lwork - indwrk; magma_int_t llwrk2 = lwork - indwk2; magma_int_t inde = 0; magma_int_t indrwk = inde + n; magma_int_t llrwk = lrwork - indrwk; magma_timer_t time=0, time_total=0, time_alloc=0, time_dist=0, time_band=0; timer_start( time_total ); #ifdef HE2HB_SINGLEGPU magmaDoubleComplex *dT1; if (MAGMA_SUCCESS != magma_zmalloc( &dT1, n*nb)) { *info = MAGMA_ERR_DEVICE_ALLOC; return *info; } timer_start( time_band ); magma_zhetrd_he2hb(uplo, n, nb, A, lda, &work[indtau1], &work[indwrk], llwork, dT1, info); timer_stop( time_band ); timer_printf( " 1 GPU seq code time zhetrd_he2hb only = %7.4f\n", time_band ); magma_free(dT1); #else magma_int_t nstream = max(3,nrgpu+2); magma_queue_t streams[MagmaMaxGPUs][20]; magmaDoubleComplex *da[MagmaMaxGPUs], *dT1[MagmaMaxGPUs]; magma_int_t ldda = ((n+31)/32)*32; magma_int_t ver = 0; magma_int_t distblk = max(256, 4*nb); #ifdef ENABLE_DEBUG printf("voici ngpu %d distblk %d NB %d nstream %d version %d \n ", nrgpu, distblk, nb, nstream, ver); #endif timer_start( time_alloc ); for( magma_int_t dev = 0; dev < nrgpu; ++dev ) { magma_int_t mlocal = ((n / distblk) / nrgpu + 1) * distblk; magma_setdevice( dev ); // TODO check malloc magma_zmalloc(&da[dev], ldda*mlocal ); magma_zmalloc(&dT1[dev], (n*nb) ); for( int i = 0; i < nstream; ++i ) { magma_queue_create( &streams[dev][i] ); } } timer_stop( time_alloc ); timer_start( time_dist ); magma_zsetmatrix_1D_col_bcyclic( n, n, A, lda, da, ldda, nrgpu, distblk ); magma_setdevice(0); timer_stop( time_dist ); timer_start( time_band ); if (ver == 30) { magma_zhetrd_he2hb_mgpu_spec(uplo, n, nb, A, lda, &work[indtau1], &work[indwrk], llwork, da, ldda, dT1, nb, nrgpu, distblk, streams, nstream, info); } else { magma_zhetrd_he2hb_mgpu(uplo, n, nb, A, lda, &work[indtau1], &work[indwrk], llwork, da, ldda, dT1, nb, nrgpu, distblk, streams, nstream, info); } timer_stop( time_band ); timer_printf(" time alloc %7.4f, ditribution %7.4f, zhetrd_he2hb only = %7.4f\n", time_alloc, time_dist, time_band ); for( magma_int_t dev = 0; dev < nrgpu; ++dev ) { magma_setdevice( dev ); magma_free( da[dev] ); magma_free( dT1[dev] ); for( int i = 0; i < nstream; ++i ) { magma_queue_destroy( streams[dev][i] ); } } #endif // not HE2HB_SINGLEGPU timer_stop( time_total ); timer_printf( " time zhetrd_he2hb_mgpu = %6.2f\n", time_total ); timer_start( time_total ); timer_start( time ); /* copy the input matrix into WORK(INDWRK) with band storage */ /* PAY ATTENTION THAT work[indwrk] should be able to be of size lda2*n which it should be checked in any future modification of lwork.*/ magma_int_t lda2 = 2*nb; //nb+1+(nb-1); magmaDoubleComplex* A2 = &work[indwrk]; memset(A2, 0, n*lda2*sizeof(magmaDoubleComplex)); for (magma_int_t j = 0; j < n-nb; j++) { len = nb+1; blasf77_zcopy( &len, A(j,j), &ione, A2(0,j), &ione ); memset(A(j,j), 0, (nb+1)*sizeof(magmaDoubleComplex)); *A(nb+j,j) = c_one; } for (magma_int_t j = 0; j < nb; j++) { len = nb-j; blasf77_zcopy( &len, A(j+n-nb,j+n-nb), &ione, A2(0,j+n-nb), &ione ); memset(A(j+n-nb,j+n-nb), 0, (nb-j)*sizeof(magmaDoubleComplex)); } timer_stop( time ); timer_printf( " time zhetrd_convert = %6.2f\n", time ); timer_start( time ); magma_zhetrd_hb2st(uplo, n, nb, Vblksiz, A2, lda2, w, &rwork[inde], &work[indV2], ldv, &work[indTAU2], wantz, &work[indT2], ldt); timer_stop( time ); timer_stop( time_total ); timer_printf( " time zhetrd_hb2st = %6.2f\n", time ); timer_printf( " time zhetrd = %6.2f\n", time_total ); /* For eigenvalues only, call DSTERF. For eigenvectors, first call ZSTEDC to generate the eigenvector matrix, WORK(INDWRK), of the tridiagonal matrix, then call ZUNMTR to multiply it to the Householder transformations represented as Householder vectors in A. */ if (! wantz) { timer_start( time ); lapackf77_dsterf(&n, w, &rwork[inde], info); magma_dmove_eig(range, n, w, &il, &iu, vl, vu, m); timer_stop( time ); timer_printf( " time dstedc = %6.2f\n", time ); } else { timer_start( time_total ); timer_start( time ); magma_zstedx_m(nrgpu, range, n, vl, vu, il, iu, w, &rwork[inde], &work[indwrk], n, &rwork[indrwk], llrwk, iwork, liwork, info); timer_stop( time ); timer_printf( " time zstedx_m = %6.2f\n", time ); timer_start( time ); magma_dmove_eig(range, n, w, &il, &iu, vl, vu, m); /* magmaDoubleComplex *dZ; magma_int_t lddz = n; if (MAGMA_SUCCESS != magma_zmalloc( &dZ, *m*lddz)) { *info = MAGMA_ERR_DEVICE_ALLOC; return *info; } magma_zbulge_back(uplo, n, nb, *m, Vblksiz, &work[indwrk + n * (il-1)], n, dZ, lddz, &work[indV2], ldv, &work[indTAU2], &work[indT2], ldt, info); magma_zgetmatrix( n, *m, dZ, lddz, &work[indwrk], n); magma_free(dZ); */ magma_zbulge_back_m(nrgpu, uplo, n, nb, *m, Vblksiz, &work[indwrk + n * (il-1)], n, &work[indV2], ldv, &work[indTAU2], &work[indT2], ldt, info); timer_stop( time ); timer_printf( " time zbulge_back_m = %6.2f\n", time ); timer_start( time ); magma_zunmqr_m(nrgpu, MagmaLeft, MagmaNoTrans, n-nb, *m, n-nb, A+nb, lda, &work[indtau1], &work[indwrk + n * (il-1) + nb], n, &work[indwk2], llwrk2, info); lapackf77_zlacpy("A", &n, m, &work[indwrk + n * (il-1)], &n, A, &lda); timer_stop( time ); timer_stop( time_total ); timer_printf( " time zunmqr_m + copy = %6.2f\n", time ); timer_printf( " time eigenvectors backtransf. = %6.2f\n", time_total ); } /* If matrix was scaled, then rescale eigenvalues appropriately. */ if (iscale == 1) { if (*info == 0) { imax = n; } else { imax = *info - 1; } d__1 = 1. / sigma; blasf77_dscal(&imax, &d__1, w, &ione); } work[0] = MAGMA_Z_MAKE( lwmin * one_eps, 0.); // round up rwork[0] = lrwmin * one_eps; iwork[0] = liwmin; magma_setdevice( orig_dev ); return *info; } /* magma_zheevdx_2stage_m */
/***************************************************************************//** Purpose ------- DSYEVD computes all eigenvalues and, optionally, eigenvectors of a real symmetric matrix A. If eigenvectors are desired, it uses a divide and conquer algorithm. The divide and conquer algorithm makes very mild assumptions about floating point arithmetic. It will work on machines with a guard digit in add/subtract, or on those binary machines without guard digits which subtract like the Cray X-MP, Cray Y-MP, Cray C-90, or Cray-2. It could conceivably fail on hexadecimal or decimal machines without guard digits, but we know of none. Arguments --------- @param[in] ngpu INTEGER Number of GPUs to use. ngpu > 0. @param[in] jobz magma_vec_t - = MagmaNoVec: Compute eigenvalues only; - = MagmaVec: Compute eigenvalues and eigenvectors. @param[in] range magma_range_t - = MagmaRangeAll: all eigenvalues will be found. - = MagmaRangeV: all eigenvalues in the half-open interval (VL,VU] will be found. - = MagmaRangeI: the IL-th through IU-th eigenvalues will be found. @param[in] uplo magma_uplo_t - = MagmaUpper: Upper triangle of A is stored; - = MagmaLower: Lower triangle of A is stored. @param[in] n INTEGER The order of the matrix A. N >= 0. @param[in,out] A DOUBLE PRECISION array, dimension (LDA, N) On entry, the symmetric matrix A. If UPLO = MagmaUpper, the leading N-by-N upper triangular part of A contains the upper triangular part of the matrix A. If UPLO = MagmaLower, the leading N-by-N lower triangular part of A contains the lower triangular part of the matrix A. On exit, if JOBZ = MagmaVec, then if INFO = 0, A contains the orthonormal eigenvectors of the matrix A. If JOBZ = MagmaNoVec, then on exit the lower triangle (if UPLO=MagmaLower) or the upper triangle (if UPLO=MagmaUpper) of A, including the diagonal, is destroyed. @param[in] lda INTEGER The leading dimension of the array A. LDA >= max(1,N). @param[in] vl DOUBLE PRECISION @param[in] vu DOUBLE PRECISION If RANGE=MagmaRangeV, the lower and upper bounds of the interval to be searched for eigenvalues. VL < VU. Not referenced if RANGE = MagmaRangeAll or MagmaRangeI. @param[in] il INTEGER @param[in] iu INTEGER If RANGE=MagmaRangeI, the indices (in ascending order) of the smallest and largest eigenvalues to be returned. 1 <= IL <= IU <= N, if N > 0; IL = 1 and IU = 0 if N = 0. Not referenced if RANGE = MagmaRangeAll or MagmaRangeV. @param[out] m INTEGER The total number of eigenvalues found. 0 <= M <= N. If RANGE = MagmaRangeAll, M = N, and if RANGE = MagmaRangeI, M = IU-IL+1. @param[out] w DOUBLE PRECISION array, dimension (N) If INFO = 0, the eigenvalues in ascending order. @param[out] work (workspace) DOUBLE PRECISION array, dimension (MAX(1,LWORK)) On exit, if INFO = 0, WORK[0] returns the optimal LWORK. @param[in] lwork INTEGER The length of the array WORK. - If N <= 1, LWORK >= 1. - If JOBZ = MagmaNoVec and N > 1, LWORK >= 2*N + N*NB. - If JOBZ = MagmaVec and N > 1, LWORK >= max( 2*N + N*NB, 1 + 6*N + 2*N**2 ). NB can be obtained through magma_get_dsytrd_nb(N). \n If LWORK = -1, then a workspace query is assumed; the routine only calculates the optimal sizes of the WORK, RWORK and IWORK arrays, returns these values as the first entries of the WORK, RWORK and IWORK arrays, and no error message related to LWORK or LRWORK or LIWORK is issued by XERBLA. @param[out] iwork (workspace) INTEGER array, dimension (MAX(1,LIWORK)) On exit, if INFO = 0, IWORK[0] returns the optimal LIWORK. @param[in] liwork INTEGER The dimension of the array IWORK. - If N <= 1, LIWORK >= 1. - If JOBZ = MagmaNoVec and N > 1, LIWORK >= 1. - If JOBZ = MagmaVec and N > 1, LIWORK >= 3 + 5*N. \n If LIWORK = -1, then a workspace query is assumed; the routine only calculates the optimal sizes of the WORK, RWORK and IWORK arrays, returns these values as the first entries of the WORK, RWORK and IWORK arrays, and no error message related to LWORK or LRWORK or LIWORK is issued by XERBLA. @param[out] info INTEGER - = 0: successful exit - < 0: if INFO = -i, the i-th argument had an illegal value - > 0: if INFO = i and JOBZ = MagmaNoVec, then the algorithm failed to converge; i off-diagonal elements of an intermediate tridiagonal form did not converge to zero; if INFO = i and JOBZ = MagmaVec, then the algorithm failed to compute an eigenvalue while working on the submatrix lying in rows and columns INFO/(N+1) through mod(INFO,N+1). Further Details --------------- Based on contributions by Jeff Rutter, Computer Science Division, University of California at Berkeley, USA Modified description of INFO. Sven, 16 Feb 05. @ingroup magma_heevdx *******************************************************************************/ extern "C" magma_int_t magma_dsyevdx_m( magma_int_t ngpu, magma_vec_t jobz, magma_range_t range, magma_uplo_t uplo, magma_int_t n, double *A, magma_int_t lda, double vl, double vu, magma_int_t il, magma_int_t iu, magma_int_t *m, double *w, double *work, magma_int_t lwork, #ifdef COMPLEX double *rwork, magma_int_t lrwork, #endif magma_int_t *iwork, magma_int_t liwork, magma_int_t *info) { const char* uplo_ = lapack_uplo_const( uplo ); const char* jobz_ = lapack_vec_const( jobz ); magma_int_t ione = 1; magma_int_t izero = 0; double d_one = 1.; double d__1; double eps; magma_int_t inde; double anrm; double rmin, rmax; double sigma; magma_int_t iinfo, lwmin; magma_int_t lower; magma_int_t wantz; magma_int_t indwk2, llwrk2; magma_int_t iscale; double safmin; double bignum; magma_int_t indtau; magma_int_t indwrk, liwmin; magma_int_t llwork; double smlnum; magma_int_t lquery; magma_int_t alleig, valeig, indeig; wantz = (jobz == MagmaVec); lower = (uplo == MagmaLower); alleig = (range == MagmaRangeAll); valeig = (range == MagmaRangeV); indeig = (range == MagmaRangeI); lquery = (lwork == -1 || liwork == -1); *info = 0; if (! (wantz || (jobz == MagmaNoVec))) { *info = -1; } else if (! (alleig || valeig || indeig)) { *info = -2; } else if (! (lower || (uplo == MagmaUpper))) { *info = -3; } else if (n < 0) { *info = -4; } else if (lda < max(1,n)) { *info = -6; } else { if (valeig) { if (n > 0 && vu <= vl) { *info = -8; } } else if (indeig) { if (il < 1 || il > max(1,n)) { *info = -9; } else if (iu < min(n,il) || iu > n) { *info = -10; } } } magma_int_t nb = magma_get_dsytrd_nb( n ); if ( n <= 1 ) { lwmin = 1; liwmin = 1; } else if ( wantz ) { lwmin = max( 2*n + n*nb, 1 + 6*n + 2*n*n ); liwmin = 3 + 5*n; } else { lwmin = 2*n + n*nb; liwmin = 1; } work[0] = magma_dmake_lwork( lwmin ); iwork[0] = liwmin; if ((lwork < lwmin) && !lquery) { *info = -14; } else if ((liwork < liwmin) && ! lquery) { *info = -16; } if (*info != 0) { magma_xerbla( __func__, -(*info) ); return *info; } else if (lquery) { return *info; } /* Quick return if possible */ if (n == 0) { return *info; } if (n == 1) { w[0] = A[0]; if (wantz) { A[0] = 1.; } return *info; } /* Check if matrix is very small then just call LAPACK on CPU, no need for GPU */ if (n <= 128) { #ifdef ENABLE_DEBUG printf("--------------------------------------------------------------\n"); printf(" warning matrix too small N=%lld NB=%lld, calling lapack on CPU\n", (long long) n, (long long) nb ); printf("--------------------------------------------------------------\n"); #endif lapackf77_dsyevd(jobz_, uplo_, &n, A, &lda, w, work, &lwork, iwork, &liwork, info); return *info; } /* Get machine constants. */ safmin = lapackf77_dlamch("Safe minimum"); eps = lapackf77_dlamch("Precision"); smlnum = safmin / eps; bignum = 1. / smlnum; rmin = magma_dsqrt(smlnum); rmax = magma_dsqrt(bignum); /* Scale matrix to allowable range, if necessary. */ anrm = lapackf77_dlansy("M", uplo_, &n, A, &lda, work); iscale = 0; if (anrm > 0. && anrm < rmin) { iscale = 1; sigma = rmin / anrm; } else if (anrm > rmax) { iscale = 1; sigma = rmax / anrm; } if (iscale == 1) { lapackf77_dlascl(uplo_, &izero, &izero, &d_one, &sigma, &n, &n, A, &lda, info); } /* Call DSYTRD to reduce symmetric matrix to tridiagonal form. */ // dsytrd work: e (n) + tau (n) + llwork (n*nb) ==> 2n + n*nb // dstedx work: e (n) + tau (n) + z (n*n) + llwrk2 (1 + 4*n + n^2) ==> 1 + 6n + 2n^2 inde = 0; indtau = inde + n; indwrk = indtau + n; indwk2 = indwrk + n*n; llwork = lwork - indwrk; llwrk2 = lwork - indwk2; magma_timer_t time=0; timer_start( time ); magma_dsytrd_mgpu(ngpu, 1, uplo, n, A, lda, w, &work[inde], &work[indtau], &work[indwrk], llwork, &iinfo); timer_stop( time ); timer_printf( "time dsytrd = %6.2f\n", time ); /* For eigenvalues only, call DSTERF. For eigenvectors, first call DSTEDC to generate the eigenvector matrix, WORK(INDWRK), of the tridiagonal matrix, then call DORMTR to multiply it to the Householder transformations represented as Householder vectors in A. */ if (! wantz) { lapackf77_dsterf(&n, w, &work[inde], info); magma_dmove_eig(range, n, w, &il, &iu, vl, vu, m); } else { timer_start( time ); magma_dstedx_m(ngpu, range, n, vl, vu, il, iu, w, &work[inde], &work[indwrk], n, &work[indwk2], llwrk2, iwork, liwork, info); timer_stop( time ); timer_printf( "time dstedc = %6.2f\n", time ); timer_start( time ); magma_dmove_eig(range, n, w, &il, &iu, vl, vu, m); magma_dormtr_m(ngpu, MagmaLeft, uplo, MagmaNoTrans, n, *m, A, lda, &work[indtau], &work[indwrk + n * (il-1)], n, &work[indwk2], llwrk2, &iinfo); lapackf77_dlacpy("A", &n, m, &work[indwrk + n * (il-1)], &n, A, &lda); timer_stop( time ); timer_printf( "time dormtr + copy = %6.2f\n", time ); } /* If matrix was scaled, then rescale eigenvalues appropriately. */ if (iscale == 1) { d__1 = 1. / sigma; blasf77_dscal(&n, &d__1, w, &ione); } work[0] = magma_dmake_lwork( lwmin ); iwork[0] = liwmin; return *info; } /* magma_dsyevd_m */